本文叙述了一组特殊类型的慢性脊髓性肌萎缩.5例均系发生于左肩和上臂部的肌萎缩且均系年轻男性患者,主要分布于C_5和C_6支配的肌节(myotome)肌萎缩停留于初发部位长达13～18年之久,其中4例后来向右上臂或左前臂和手肌扩延,另一例向腿和脸肌扩延.发现肌电图检查总是比临床检查显示较大的受累范围. This article describes a group of special types of chronic spinal muscular atrophy, all of which occurred in young men with atrophy of the left shoulder and upper arm, all of which were mainly found in the myotome muscle atrophy of C_5 and C_6 In the first episode of up to 13 to 18 years, of which 4 were later to the right upper arm or left forearm and hand muscle extension, the other to the legs and facial muscle extension found EMG examination is always more than the clinical examination showed Larger affected area.