James H E, Mulcahy J J, Walsh J W, Kaplan G W
Neurosurgery. 1979 Jun;4(6):521-3. doi: 10.1227/00006123-197906000-00005.
The mechanical activity of the anal sphincter can be translated into electrical activity and recorded on graph paper or an oscilloscope. The activity of the anal sphincter may be extrapolated to activity of the external urethral sphincter because both are striated muscles innervated by the pudendal nerve that arises from S-2, S-3, and S-4. Stimulation of these nerves causes contraction of the sphincter muscles, and a deflection of the recording device occurs. This technique was employed intraoperatively in monitoring operations on the conus medullaris and sacral nerve roots in 10 patients with spinal dysraphism (age range, 3 weeks to 15 years). Their diagnoses were tethered conus, 4; lipomeningocele, 3; spinal hamartoma, 1; syringocele, 1; and sacral arachnoiditis, 1. With general anesthesia, and the patient in the prone position, an electrode-containing anal plug was inserted or two needle electrodes were inserted into the anal sphincter muscle. The electrodes were connected to the electromyography recording stylus of the urodynamic bladder diagnostic unit. During the spinal operation, whenever a structure could not be identified clearly, it was stimulated with the disposable electrical stimulator and, if oscillations of the stylus occurred (indicating contraction of the anal sphincter), the structure was preserved. This technique permitted spinal operations in these 10 patients without changes in neurological or urological function.
肛门括约肌的机械活动可转化为电活动，并记录在图纸或示波器上。肛门括约肌的活动可外推至尿道外括约肌的活动，因为二者均为受来自S-2、S-3和S-4的阴部神经支配的横纹肌。刺激这些神经会导致括约肌收缩，记录装置出现偏转。该技术在术中用于监测10例脊柱裂患者（年龄范围为3周龄至15岁）的圆锥脊髓和骶神经根手术。他们的诊断分别为：脊髓栓系4例；脂肪瘤型脊膜膨出3例；脊髓错构瘤1例；脊髓空洞1例；骶蛛网膜炎1例。全身麻醉下，患者取俯卧位，插入含电极的肛门塞或将两根针电极插入肛门括约肌。电极连接到尿动力学膀胱诊断装置的肌电图记录笔。在脊柱手术过程中，每当无法清晰识别某个结构时，就用一次性电刺激器对其进行刺激，如果记录笔出现振荡（表明肛门括约肌收缩），则保留该结构。该技术使这10例患者的脊柱手术未出现神经或泌尿功能改变。
