J Neurogastroenterol Motil.  2019 Jul;25(3):423-435. 10.5056/jnm18196.

Defective Conduction of Anorectal Afferents Is a Very Prevalent Pathophysiological Factor Associated to Fecal Incontinence in Women

• Mundet L
• Cabib C
• Ortega O
• Rofes L
• Tomsen N
• Marin S
• Chacón C
• Clavé P

• KMID: 2454641
• DOI: http://doi.org/10.5056/jnm18196

Abstract

BACKGROUND/AIMS
Fecal incontinence (FI) is a prevalent condition among women. While biomechanical motor components have been thoroughly researched, anorectal sensory aspects are less known. We studied the pathophysiology of FI in community-dwelling women, specifically, the conduction through efferent/afferent neural pathways.
METHODS
A cross-sectional study was conducted on 175 women with FI and 19 healthy volunteers. The functional/structural study included anorectal manometry/endoanal ultrasound. Neurophysiological studies including pudendal nerve terminal motor latency (PNTML) and sensory-evoked-potentials to anal/rectal stimulation (ASEP/RSEP) were conducted on all healthy volunteers and on 2 subgroups of 42 and 38 patients, respectively.
RESULTS
The main conditions associated with FI were childbirth (79.00%) and coloproctological surgery (37.10%). Cleveland score was 11.39 ± 4.09. Anorectal manometry showed external anal sphincter and internal anal sphincter insufficiency in 82.85% and 44.00%, respectively. Sensitivity to rectal distension was impaired in 27.42%. Endoanal ultrasound showed tears in external anal sphincter (60.57%) and internal anal sphincter disruptions (34.80%). Abnormal anorectal sensory conduction was evidenced through ASEP and RSEP in 63.16% and 50.00% of patients, respectively, alongside reduced activation of brain cortex to anorectal stimulation. In contrast, PNTML was delayed in only 33.30%. Stools were loose/very loose in 56.70% of patients.
CONCLUSIONS
Pathophysiology of FI in women is mainly associated with mechanical sphincter dysfunctions related to either muscle damage or, to a lesser extent, impaired efferent conduction at pudendal nerves. Impaired conduction through afferent anorectal pathways is also very prevalent in women with FI and may play an important role as a pathophysiological factor and as a potential therapeutic target.

Keyword

Anorectal physiology; Evoked potentials; Fecal incontinence; Pathophysiology; Pudendal nerve terminal motor latency

MeSH Terms

Anal Canal
Brain
Cross-Sectional Studies
Evoked Potentials
Fecal Incontinence*
Female
Healthy Volunteers
Humans
Manometry
Neural Pathways
Parturition
Pudendal Nerve
Tears
Ultrasonography