運動單元數目指標：正常人第一背側骨間肌運動單元數目之估測

Motor Unit Number Index: Estimation of the Number of Motor Units in the First Dorsal Interosseous Muscle of Normal Subjects

詹瑞棋(Rai-Chi Chan) ； 徐道昌(Tao-Chang Hsu)

《中華民國復健醫學會雜誌》 16期 (1988/12) Pp. 46-51

摘要

本研究之目的在使用常規肌電診斷的技巧來估測第一背側骨間肌運動單元的數日。以34位正常年輕人之第一背側骨間肌作研究對象，每位均施以尺神經之常規神經傳導檢查，而在第一背側骨間肌上分別以表面盤式電極及同軸針極記錄最大肌肉誘發動作電位的全表面積、負相表面積、負相振幅及尖端振幅。另外用同軸針極作肌電圖之運動單元分析，求得平均運動單元之表面積及振幅。將最大肌肉誘發電位之表面積或振幅除以個別運動單元之表面積或振幅，即為代表運動單元數目的指標。研究結果發現在各種不同的計算方式中，以表面電極之全表面積除以運動單元表面積的結果(111)最接近實際解剖值(119)，但是無論在表面電極或是針極記錄，全表面積與負相表面積、尖端振幅與負相振幅間都是固定的比例關係，而以振幅來計算運動單元指標時變異性較大。本文並將討論各項影響的因素以及運動單元指標之臨床實用價值。

並列摘要

The purpose of this study was to estimate the number of motor unit in the first dorsal interosseous muscle by using the routine electrodiagnostic techniques. 34 young adult volunteers was included in this study, each subject recevied the following procedures on the first dorsal interosseous muscle: 1. Surface recording of the total surface area, the area under the negative phase, peak amplitude and the base line to negative peak amplitude of the maximal evoked muscle action potential. 2. Same recording parameters but change the recording electrode to concentric needle. 3. Motor unit potential analysis with concentric needle to get the averaged surface area and amplitude of single motor unit. Motor unit number index was derived by dividing the surface area/amplitude of the maximal tcsponsc by the single motor unit area/amplitude, the indexes derived from different parameters were compared to the true anatomical calculation done by Feinstein.
The result disclosed that the motor unit number index derived from surface recording total area divided by single unit area (111) was close to anatomical data (119). There is a fixed ratio between the total surface area and the area under negative phase, peak amplitude and baseline to negative peak amplitude. The clinical application of motor tunit number index and factors contributing the these results will be further discussed.

並列關鍵字

motor unit number index ； surface srea ； amplitude