Weber J, Beuret-Blanquart F, Ducrotte P, Touchais J Y, Denis P
Groupe de Biochimie et de Physiopathologie Digestive et Nutritionnelle, UER Médecine et Pharmacie, Rouen, France.
Dis Colon Rectum. 1991 May;34(5):409-15. doi: 10.1007/BF02053693.
Six patients with complete transection of the spinal cord and six healthy volunteers were examined by using anorectal manometry together with electromyographic (EMG) recording of the external anal sphincter composed of striated muscle. Anal pressure and EMG activity of the external anal sphincter were continuously recorded at rest and during gradual rectal distention (10, 20, 30, 40, and 50 ml) by means of an air-filled balloon eliciting a rectoanal inhibitory reflex (RAIR) at the upper part, and an inflation reflex (IR) at the lower part of the anal canal. All patients and controls had a RAIR for each rectal distention volume. A relationship between the duration of the RAIR and the rectal distention volume was present in controls only. In controls the IR was present for each rectal distention volume, whereas it was present in only one patient for a 40-ml volume. During the resting period, all controls showed continuous tonic EMG activity of the external anal sphincter, but after 30 minutes all the patients showed a decrease and ultimately in five cases a disappearance of the tonic EMG activity of the external anal sphincter. In spinal patients, the presence or absence of EMG activity of the external anal sphincter did not modify the anal canal pressure. These results indicate that: 1) the tonic EMG activity of the external anal sphincter seems to be under the control of supraspinal structures, because in spinal patients it disappears in the absence of sensitive inputs toward the spinal cord; 2) the absence of EMG activity at rest indicates that the external anal sphincter is not implicated in the RAIR disturbances observed in spinal patients; 3) the IR is not a spinal reflex but is under voluntary control, because it is not present in spinal humans; 4) in spinal humans the tonic EMG activity of the external anal sphincter does not play a role in the maintenance of the anal pressure at rest.
对6例脊髓完全横断患者和6名健康志愿者进行了肛管直肠测压检查，并同时记录了由横纹肌组成的肛门外括约肌的肌电图（EMG）。通过一个充气球囊在上部引发直肠肛门抑制反射（RAIR）、在肛管下部引发膨胀反射（IR），在静息状态以及逐渐直肠扩张（10、20、30、40和50毫升）过程中持续记录肛门压力和肛门外括约肌的肌电图活动。所有患者和对照组在每个直肠扩张容积下均出现RAIR。仅在对照组中，RAIR持续时间与直肠扩张容积之间存在关联。在对照组中，每个直肠扩张容积下均出现IR，而在患者中，仅1例在40毫升容积时出现IR。在静息期，所有对照组均显示肛门外括约肌持续的紧张性肌电图活动，但30分钟后，所有患者均出现活动减少，最终5例患者的肛门外括约肌紧张性肌电图活动消失。在脊髓损伤患者中，肛门外括约肌肌电图活动的有无并不改变肛管压力。这些结果表明：1）肛门外括约肌的紧张性肌电图活动似乎受脊髓以上结构的控制，因为在脊髓损伤患者中，由于缺乏向脊髓的感觉输入，该活动消失；2）静息时缺乏肌电图活动表明肛门外括约肌与脊髓损伤患者中观察到的RAIR紊乱无关；3）IR不是脊髓反射，而是受自主控制，因为在脊髓损伤患者中不存在该反射；4）在脊髓损伤患者中，肛门外括约肌的紧张性肌电图活动在静息时维持肛管压力方面不起作用。
