Hasegawa O, Matsumoto S, Iino M, Kirigaya N, Mimura E, Wada N, Gondo G
Department of Neurology & Neurosurgery, Yokohama City University School of Medicine, Japan.
No To Shinkei. 2001 Feb;53(2):161-4.
Prevalence of median to ulnar anastomosis in the forearm(Martin-Gruber anastomosis; MGA) to the first dorsal interosseous(FDI), abductor digiti quinti (ADQ) and adductor pollicis(AP) was investigated. Subjects contained 106 patients with normal nerve conduction or patients with various neuropathies. Recording electrodes were placed on the motor point of FDI, ADQ and AP. Supramaximal stimulations were given to the median and ulnar nerves at the wrist or above the elbow. The diagnosis of MGA was made by the following criteria; amplitude of compound muscle action potential(CMAP) increased after elbow stimulation as compared with the wrist stimulation in median nerve conduction studies. The corresponding decrease in CMAP amplitude was found after above elbow stimulation as compared with the wrist stimulation in ulnar nerve conduction studies. No MGA was found in 80(75%) out of 106 patients. MGA to FDI was found in all 26 patients who had MGA. MGA to ADQ and AP was found in 11% and 10% of the patients, respectively. Only 8 out of 26 patients had MGA to all 3 muscles. In the presence of MGA median motor nerve conduction studies demonstrate larger CMAP, with a small initial positivity, after elbow stimulation than after wrist stimulation. And moreover, ulnar motor nerve conduction studies reveal a conduction block-like finding in the forearm. In this study MGA was found in 25% of the patient to FDI, in 11% to ADQ and in 10% to AP. Although a very small MGA might be overlooked in our method, such a small MGA doesn't mislead us into erroneous interpretation of motor nerve conduction studies.
研究了前臂中从正中神经到尺神经的吻合（Martin-Gruber吻合；MGA）至第一背侧骨间肌（FDI）、小指展肌（ADQ）和拇收肌（AP）的发生率。研究对象包括106例神经传导正常的患者或患有各种神经病变的患者。记录电极置于FDI、ADQ和AP的运动点上。在腕部或肘部上方对正中神经和尺神经进行超强刺激。MGA的诊断依据以下标准：在正中神经传导研究中，与腕部刺激相比，肘部刺激后复合肌肉动作电位（CMAP）的波幅增加。在尺神经传导研究中，与腕部刺激相比，肘部上方刺激后CMAP波幅相应降低。106例患者中有80例（75%）未发现MGA。在所有26例有MGA的患者中均发现了至FDI的MGA。分别有11%和10%的患者发现了至ADQ和AP的MGA。26例患者中只有8例对所有3块肌肉均有MGA。在存在MGA的情况下，正中运动神经传导研究显示，肘部刺激后CMAP较大，初始正波较小，而腕部刺激后则不然。此外，尺神经运动传导研究显示前臂有类似传导阻滞的表现。在本研究中，25%的患者发现至FDI的MGA，11%至ADQ，10%至AP。尽管我们的方法可能会忽略非常小的MGA，但这种小的MGA不会使我们对运动神经传导研究产生错误的解读。
