Sørensen M, Nielsen M B, Pedersen J F, Christiansen J
Department of Surgery D, Glostrup Hospital, University of Copenhagen, Denmark.
Dis Colon Rectum. 1994 Feb;37(2):138-43. doi: 10.1007/BF02047535.
The aim of our study was to investigate internal anal sphincter electromyographic signals.
Electromyography of the internal anal sphincter was performed with platinum wire electrodes in six healthy volunteers (three males and three females), inserted under endosonographic guidance. Platinum wire electrodes were also inserted into the external anal sphincter. Activity of both the internal and external and sphincter in a 40-second period was measured.
Internal anal sphincter median activity was 22.1 (range, 5.5-67.6) microV. Slow-wave activity was 47 cycles/minute (range, 34-55 cycles/minute). After inflation of a rectal balloon with air until a constant relaxation of the anal canal was obtained, a decrease in internal and sphincter activity to 15.9 (1.2-31.3) microV as well as a decrease in slow-wave activity to 34 cycles/minute (range, 27-40 cycles/minute) was found. The original internal anal sphincter EMG was resumed after deflation of the rectal balloon. External anal sphincter median activity was 3.1 (range, 0.77-18.6) microV. During inflation of the rectal balloon, a reflex increase in external sphincter EMG activity was found. With the rectal balloon fully inflated a part of this increase was still present, 11.0 (1.9-24.6) microV. In some of the subjects, this increased activity was superimposed on the internal anal sphincter recordings as well. During a voluntary squeeze it was not possible to identify internal anal sphincter activity due to activity of the external anal sphincter totally overriding the internal anal sphincter signal.
Precise EMG recordings from the internal anal sphincter is possible with endosonographic guidance of the electrodes, except during voluntary squeezing of the external and sphincter.
本研究旨在探究肛门内括约肌肌电信号。
在6名健康志愿者（3名男性和3名女性）中，于超声内镜引导下将铂丝电极插入肛门内括约肌进行肌电图检查。铂丝电极也插入肛门外括约肌。测量40秒内肛门内、外括约肌的活动情况。
肛门内括约肌的中位活动为22.1（范围5.5 - 67.6）微伏。慢波活动为47次/分钟（范围34 - 55次/分钟）。向直肠气囊充气直至肛管持续松弛后，发现肛门内括约肌活动降至15.9（1.2 - 31.3）微伏，慢波活动降至34次/分钟（范围27 - 40次/分钟）。直肠气囊放气后，肛门内括约肌肌电图恢复至初始状态。肛门外括约肌的中位活动为3.1（范围0.77 - 18.6）微伏。直肠气囊充气期间，发现肛门外括约肌肌电活动有反射性增加。直肠气囊完全充气时，这种增加仍有部分存在，为11.0（1.9 - 24.6）微伏。在一些受试者中，这种增加的活动也叠加在肛门内括约肌记录上。在自主收缩时，由于肛门外括约肌的活动完全覆盖了肛门内括约肌信号，无法识别肛门内括约肌的活动。
在电极的超声内镜引导下，可以精确记录肛门内括约肌的肌电图，但在自主收缩肛门外括约肌时除外。
