睡眠時斜方肌表皮肌電訊號的特性分析

The characteristics of surface electromyography of trapezius muscle during sleep

康峻宏(Jiunn-Horng Kang)

指導教授 ： 張權維

國立臺灣大學/醫學院/臨床醫學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.00441

摘要

研究背景及目的
斜方肌是人類穩定肩頸部的一塊重要的姿勢肌。斜方肌肌痛症則是臨床上十分常見，也是職業醫學中重要的慢性問題之一。目前對於產生斜方肌肌肉痛的機轉仍不十分清楚。之前的假說認為斜方肌的表皮肌電訊號可能與疼痛的發生有關。有研究發現斜方肌在一般休息狀態會出現低強度自發性的收縮，而在上肢工作或是有心智壓力時會改變運動神經元活性使得收縮模式改變，同時，斜方肌肌痛症患者在處於心智壓力的狀態下，肌電活性會上升，而且需較長時間才會恢復。因此有學者認為此種不正常的活性會因為長時間低強度的肌肉收縮而所造成的肌肉疲勞及微創傷。另一方面亦有研究發現在有疼痛的受試者中，夜間的斜方肌肌電訊號也會出現較高的活性，而指出這類患者可能在夜間的斜方肌不正常肌電訊號和疾病發生有相關。要回答此一問題則需先針對一般人睡眠中斜方肌的肌電活性做一深入探討。最近的研究發現在健康人睡眠時，斜方肌表皮肌電圖活性會出現極低頻率震盪 (<0.3 Hz)的現象，並指出這個發現可用以觀察運動路徑的活性。由於目前仍無文獻探討對於斜方肌肌電圖活性特色及與睡眠中腦波之關係。本研究之目的在於針對一般人在睡眠中斜方肌的肌電訊號做一定量及定性分析，同時分析肌電訊號與腦波訊號的相關性。本研究的結果可以建立正常人睡眠斜方肌表皮肌電圖變化的常模，同時也可以應用於進一步比較斜方肌肌痛患者的睡眠肌電圖，以作為臨床上的應用。

研究方法
共有25名健康女性接受研究測試。受試者在最近一個月內無肩頸疼痛及睡眠相關問題的症狀。本研究監測採用美國睡眠醫學會建議標準睡眠多項生理檢查之頻道，同時合併雙側斜方肌之表皮肌電圖監測。每一個健康受測者，皆須完成一週睡眠日誌及PSQI，ESS，CHQ-12之量表。在進行夜間多項生理檢查之前三晚，禁止熬夜或是服用任何藥物。為避免第一夜效應，若受試者之監測睡眠效率小於85%，則須監測第二晚。我們將所記錄的斜方肌肌電圖及腦波訊號原始訊號，先經過合適濾波處理以減少干擾，再計算其每16秒間距的快速傅立葉之頻譜分布。並觀察其與同時的腦波不同頻帶頻譜強度變化的相關性。最後，我們計算出斜方肌肌電訊號及腦波訊號的耦合頻譜訊號，並分析該頻譜在不同睡眠時期下極低頻訊號強度的變化。研究採用paired t-test比較雙側斜方肌表皮肌電訊號的差異。利用Pearson correlation test分析斜方肌肌電訊號極低頻譜強度與不同的腦波頻譜帶強度的相關性。One-way ANOVA分析不同時期，極低頻耦合訊號頻譜強度的差異。

研究結果
我們發現在一般女性睡眠中，斜方肌肌電訊號會呈現低強度的訊號，其均方根約為峰值均方根強度的1.3 ± 0.4%。分析斜方肌肌電訊號頻譜發現確實會有間斷性出現極低頻震盪之情形。其極低頻震盪維持的時間約為數十秒至一小時左右，總長度平均約占整體睡眠時間的42.6 ± 19.2 %。進一步分析極低頻震盪的肌電訊號的頻譜強度，發現會與腦波相同頻帶的頻譜的強度成有意義的正相關 (平均相關係數：右r = 0.47,左 r = 0.39)，然而對於相對高頻(delta、theta、alpha、beta)頻帶的腦波頻譜，其相關性則較不一定。進一步研究顯示在極低頻頻譜上肌電訊號及腦波會有間歇耦合的現象，此種情形在淺睡期最為明顯。

結論
我們的研究證實睡眠時斜方肌肌電訊號會有極低頻率震盪的情形，且為第一個敘述睡眠腦波與肌電訊號相關性之研究。本研究結果可供進一步運用於慢性斜方肌痛與其他睡眠相關運動障礙患者的研究。

關鍵字

斜方肌 ； 表皮肌電圖 ； 睡眠 ； 腦電圖 ； 睡眠多項生理檢查

並列摘要

Background
Trapezius muscle is a posture muscle to maintain human shoulder-neck stability. Trapezius myalgia (TM) is a common problem in the general clinic. Previous studies indicated TM may be related to mal-posture or biomechanical loading which result in microtrauma of muscle microstructure. However, the correlation of pain and surface electromyographic (sEMG) findings of TM patients is low or insignificant in many studies. However, elevated of sEMG activities of trapezius during sleep was showed in TM patients and the mechanism was unknown. There were still scanty studies to explore the sEMG characteristics of trapezius muscle during sleep. A recent study showed a very low frequency (VLF) oscillation of trapezius sEMG occurred during sleep. This phenomenon may be related to oscillation activities of motor cortex during sleep. Analysis the trapezius sEMG data with other electrophysiological data during sleep in healthy subjects is a necessary to understand the trapezius. Our study’s goal is to analyze the sEMG pattern of trapezius muscles and their association with EEG during sleep.

Materials and Methods
25 healthy female subjects were recruited for complete polysomnographic studies with additional sEMG recording of bilateral trapezius muscles. The raw data of EEG and sEMG of trapezius were extracted and processed. Root mean square (RMS) of sEMG of bilateral trapezius muscle was calculated. Fast Fournier Transform (FFT) of 16-s window of two signals was analyzed. Coupling spectrum of EEG and contralateral sEMG signal was computed by calculated the product of the power of two signals in every frequency. Paired-t test and Pearson’s correlation were applied to analyze the difference between bilateral sides and correlation of power spectrum between EEG and sEMG of trapezius muscles. One way ANOVA was applied to compare the VLF power of coupling spectrum among the sleep stages.

Results and Conclusion
The trapezius sEMG had low-level activities during sleep and the mean of RMS was 1.3 % of RMS of maximal contraction. We confirmed that the VLF oscillation of trapezius sEMG signals occurred intermittently during sleep. The mean duration of occurrence of VLF of trapezius sEMG was 96 seconds. The mean of longest duration of VLF was about 27 minutes. The power of VLF of trapezius sEMG spectrum was positively correlated with the power of VLF of EEG spectrum significantly (mean right r = 0.47, left r = 0.39). The power of coupling spectrum of VLF of two signals was highest during stage 1/2 during sleep (p = 0.03). To our knowledge, this is the first study to describe the relationship between trapezius sEMG and EEG during sleep. These results of our study will help us to establish the norm data of trapezius sEMG change of healthy human during sleep. Further studies to compare the normal and TM subjects will be conducted for clinical application.

並列關鍵字

Trapezius ； surface electromyography ； Sleep ； electroencephalography ； polysomnography ； oscillation

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