Study of the cortico-anorectal neurophysiology in women with fecal incontinence.

Abstract

Background: Fecal incontinence (FI) is a prevalent condition that disproportionately impacts women. Although sphincter biomechanics are well studied, the integrity of the cortico-anal motor pathway remains elusive. We evaluated the cortico-spino-anorectal pathway in women with FI against age-matched (AM-HV) and young healthy (Y-HV) volunteers.

Methods: Observational study with 18 women with FI (mean age: 63.4±11.1), 15 AM-HV (60.7±9.01, and 15 Y-HV (24.2±5.39), conducted in a tertiary hospital. Participants underwent clinical evaluation, high-resolution anorectal manometry (HRAM), endoanal ultrasound, and transcranial/translumbosacral magnetic stimulation to assess anorectal motor evoked potentials (MEP). Clinical severity was measured with St. Mark's score, and quality of life with FIQL and EQ5D.

Results: Patients had longer MEP latencies than AM-HV in the cortico-anal (25.93±3.67 ms vs 22.89±1.38 ms) andright lumbo-rectal segments (5.64±1.35 ms vs4.39±1.27 ms; p<0.05) but not in the tibial segment (control)(33.35±2.88 ms vs 32.08±2.05 ms; p>0.05). However, tibial latencies were longer in AM-HV compared to Y-HV (32.08±2.05 ms vs 29.21±2.75 ms; p=0.003). In FI, 41.1% had cortico-anorectal impairments, 50% lumbo-anal, and 44.4% sacral. Overall, 82.4% showed delayed latencies in at least one of the 12 segments. HRAM revealed 83.24% had external anal sphincter (EAS) dysfunction, 40% internal sphincter dysfunction, and 23.57% both. MEP latencies inversely correlated with EAS squeeze strength. FI patients had significantly poorer EQ5D scores compared to both control groups.

Conclusion: Women with FI show significant neuropathy in the cortico-spino-anorectal pathway linked to impaired anorectal function. These findings underscore the brain-gut axis's role in FI pathophysiology, advocating for advanced neurophysiological diagnostics and targeted interventions.