Electrodiagnosis of Median-to-Ulnar Nerve Anastomosis and Anomalous Innervation of the Intrinsic Hand Muscles

正中神經到尺神經神經吻合與手內肌群異常支配之肌電診斷

吳致良(Chih-Liang Wu) ； 張奐(Huann Chang) ； 孫丕昌(Pi-Chang Sun) ； 廖淑芬(Su-Fen Liao) ； 詹瑞棋(Rai-Chi Chan)

《中華民國復健醫學會雜誌》 25卷2期 (1997/12) Pp. 149-154

摘要

正中神經到尺神經之神經吻合(Martin-Gruber anastomosis，MGA)是前臂常見的神經異常支配。其臨床意義在於透過二者之神經吻合，正中神經可支配手部尺神經肌肉群，而不受尺神經病變影響，另外在同時合併有MGA及腕道症候群患者，其特別之神經傳導檢查之發現也可提供作診斷之參考。故本研究目的在統計國人發生正中神經到尺神經之神經吻合比例，與手肌群異常支配分佈情形。
以五十位志願受試者一百隻手為測試對象，表面電極貼於魚際肌，小魚際肌與第一背側骨間肌，分別用電刺激肘部與腕部之正中神經與尺神經，以 Nicolet Viking II 肌電圖儀同時記錄複合肌肉動作電位。結果顯示存在正中神經到尺神經之神經吻合有十二隻手(12%)，手內肌群異常支配分佈:魚際肌佔17%，小魚際肌佔17%，第一背側骨間肌佔92%，本研究並未發現尺神經到正中尺神經之神經吻合。我們的結論為正中神經到尺神經之神經吻合在國人約有12%的發生率，手內肌群異常支配以第一背側骨間肌為主。在臨床上如有尺神經病變或腕道症候群的病人做肌電檢查時，建議用本研究所提供的方法過濾，注意有無正中神經到尺神經神經吻合存在，以避免診斷不夠精確所帶來的困擾。

關鍵字

正中神經到尺神經神經吻合 ； 表面電極 ； 手內肌群

並列摘要

Communication between the median and ulnar nerves is a common anomaly in the forearm (Martin-Gruber anastomosis, MGA). The knowledge of these anastomoses and the resulting anomalous innervation patterns is of crucial importance to the clinicians and electromyographers in the performance of nerve conduction and electromyographic studies in normal patients and those with peripheral nerve lesions. One hundred forearms (fifty cases) were examined for median-to-ulnar or ulnar-to-median nerve anastomoses using surface electrodes. We found a motor median-to-ulnar nerve anastomosis occurring in 12% of forearms studied. The incidence of innervation of the different intrinsic hand muscles: abductor pollicis brevis (APB) 17%; abductor digiti quinti (ADQ) 17%; first dorsal interosseus (FDI) 92%. In conclusion, the incidence of MGA in our study corresponds well with the results of other authors. No case of motor ulnar-to-median nerve anastomosis in the forearm could be found. Electromyographers and clinicians need to consider the possibility of a MGA when the hand is evaluated for nerve dysfunction.

並列關鍵字

median-to-ulnar nerve anastomosis ； surface electrode ； intrinsic hand muscles