Weidner A C, Sanders D B, Nandedkar S D, Bump R C
Division of Gynecologic Specialties, Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC 27710, USA.
Am J Obstet Gynecol. 2000 Nov;183(5):1249-56. doi: 10.1067/mob.2000.107630.
Our aims were to introduce a method of digital quantitative electromyography of the levator ani and external anal sphincter muscles and to establish reference values.
Fifteen nulliparous, symptom-free women underwent concentric needle electromyographic examination of the levator ani and external anal sphincter. We sampled the levator ani transvaginally at 4 sites and the external anal sphincter at 2 sites. The signal was filtered and amplified, and digital recordings were made at 3 levels of voluntary activation at each site. Analyses of motor unit action potentials and interference patterns were performed with the use of these taped signals. Normal ranges were generated and compared with those established for other striated muscles.
The mean age of the subjects was 28.7+/-7.5 years. A median of 24 motor unit action potentials was recorded in each levator ani, and a median of 6 was recorded in each external anal sphincter. Parameters of the levator ani action potentials were significantly greater than those of the external anal sphincter in amplitude (0.48 vs. 0.37 mV; P =.001), duration (10.40 vs. 8.27 ms; P =.002), number of turns per second (2. 80 vs. 2.28; P<.001), and area (0.65 vs. 0.36; P<.001). Parameters of the interference patterns were significantly greater in the levator ani than in the external anal sphincter in number of turns per second (241.6 vs. 183.9; P =.015), amplitude (302.7 vs. 225.3 microV; P<.0001), activity (95.6 vs 61.2; P =.004), envelope size (861.1 vs 567.6 microV; P<.0001), and number of small segments (105. 8 vs 81.4; P =.047). There were no significant differences between levator ani, external anal sphincter, and published parameters from the biceps muscle with regard to amplitude and duration of motor unit action potentials.
Electromyography of the levator ani and external anal sphincter is feasible and well tolerated. Our findings confirm that the levator ani muscle has larger, more readily recruited motor units than does the external anal sphincter. Ranges for important quantitative electromyographic parameters for these muscles are similar to those published for the biceps.
我们的目标是介绍一种用于肛提肌和肛门外括约肌的数字定量肌电图方法，并建立参考值。
15名未生育、无症状的女性接受了肛提肌和肛门外括约肌的同心针肌电图检查。我们经阴道在4个部位采集肛提肌样本，在2个部位采集肛门外括约肌样本。信号经过滤波和放大，并在每个部位的3个自主激活水平下进行数字记录。利用这些录制的信号对运动单位动作电位和干扰模式进行分析。生成正常范围并与其他横纹肌的正常范围进行比较。
受试者的平均年龄为28.7±7.5岁。每条肛提肌记录到的运动单位动作电位中位数为24个，每条肛门外括约肌记录到的中位数为6个。肛提肌动作电位的参数在幅度（0.48对0.37 mV；P = 0.001）、持续时间（10.40对8.27 ms；P = 0.002）、每秒转折数（2.80对2.28；P<0.001）和面积（0.65对0.36；P<0.001）方面均显著大于肛门外括约肌。干扰模式的参数在每秒转折数（241.6对183.9；P = 0.015）、幅度（302.7对225.3 μV；P<0.0001）、活性（95.6对61.2；P = 0.004）、包络大小（861.1对567.6 μV；P<0.0001）和小片段数量（105.8对81.4；P = 0.047）方面，肛提肌显著大于肛门外括约肌。在运动单位动作电位的幅度和持续时间方面，肛提肌、肛门外括约肌与已发表的肱二头肌参数之间无显著差异。
肛提肌和肛门外括约肌的肌电图检查是可行的，且耐受性良好。我们的研究结果证实，肛提肌比肛门外括约肌具有更大、更易募集的运动单位。这些肌肉重要的定量肌电图参数范围与已发表的肱二头肌参数相似。
