van Meegdenburg Maxime M, Heineman Erik, Broens Paul M A
1 Anorectal Physiology Laboratory, Department of Surgery, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands 2 Division of Pediatric Surgery, Department of Surgery, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
Dis Colon Rectum. 2015 Dec;58(12):1186-93. doi: 10.1097/DCR.0000000000000497.
Conscious external anal sphincter contraction is mediated by the pudendal nerve. Pudendal neuropathy is, therefore, believed to result in fecal incontinence. Until urge sensation is experienced, fecal continence is maintained by unconscious external anal sphincter contraction, which is regulated by the anal-external sphincter continence reflex. The innervation of unconscious contraction is yet unknown.
We aimed to determine whether unconscious contraction is mediated by the pudendal nerve and whether age influences unconscious contraction.
This was a retrospective comparative study.
The study was conducted in a tertiary care center.
Seventy adult patients experiencing defecation problems who underwent anorectal function tests were included in this study.
Conscious and unconscious contractions were compared between patients with and without pudendal neuropathy. Conscious contraction was defined by maximum anal sphincter contractility, unconscious contraction by pressure in the anal canal at maximum tolerable or retainable sensation during the balloon retention test.
Unconscious contraction did not differ significantly between patients with pudendal neuropathy and non-pudendal neuropathy patients, whereas conscious contraction was significantly lower in patients with pudendal neuropathy. Multiple linear regression analyses demonstrated that unconscious contraction, in contrast to conscious contraction, was not predicted significantly by age and anal electrosensitivity at 2 cm, which represents pudendal neuropathy. Patients with pudendal neuropathy were significantly older than patients with nonpudendal neuropathy.
The pudendal nerve motor latency and EMG tests were not performed.
The pudendal nerve does not mediate unconscious external anal sphincter contraction. Pudendal neuropathy alone, therefore, results in urge incontinence rather than in complete fecal incontinence. Unconscious contraction appears not to be influenced by age. Therefore, most of the elderly patients experience urge incontinence rather than complete fecal incontinence.
肛门外括约肌的有意识收缩由阴部神经介导。因此，阴部神经病变被认为会导致大便失禁。在出现便意之前，大便失禁是由肛门外括约肌的无意识收缩维持的，而这种无意识收缩由肛门外括约肌节制反射调节。无意识收缩的神经支配尚不清楚。
我们旨在确定无意识收缩是否由阴部神经介导，以及年龄是否会影响无意识收缩。
这是一项回顾性比较研究。
该研究在一家三级医疗中心进行。
本研究纳入了70名接受肛肠功能测试的有排便问题的成年患者。
比较有和没有阴部神经病变的患者的有意识和无意识收缩。有意识收缩通过肛门括约肌最大收缩力来定义，无意识收缩通过气囊留置试验中在最大耐受或可保留感觉时肛管内的压力来定义。
阴部神经病变患者和非阴部神经病变患者的无意识收缩没有显著差异，而阴部神经病变患者的有意识收缩明显较低。多元线性回归分析表明，与有意识收缩不同，无意识收缩并不能由年龄和2厘米处的肛门电敏感性（代表阴部神经病变）显著预测。阴部神经病变患者的年龄显著大于非阴部神经病变患者。
未进行阴部神经运动潜伏期和肌电图测试。
阴部神经并不介导肛门外括约肌的无意识收缩。因此，仅阴部神经病变会导致急迫性失禁而非完全大便失禁。无意识收缩似乎不受年龄影响。因此，大多数老年患者经历的是急迫性失禁而非完全大便失禁。
