Abnormal neuronal response to rectal and anal stimuli in patients with idiopathic fecal incontinence

Abstract

IFI seems to be associated with impaired ano-rectal sensory functions in both the afferent fibers to the brain and the cortical processing of anal sensory pathways. This may play a central role for the pathogenesis of IFI.

Brain responses to mechanical rectal stimulation in patients with faecal incontinence: an fMRI study

“…Abnormal central processing of rectal sensation during distension appears important in the development of FI . A recent study revealed that cortical evoked potentials had significantly longer latency in patients with FI compared to controls, although it was unable to determine if this aberrant communication between the gut and the brain is at the level of the rectum, peripheral nerves or the central nervous system . Interestingly, somatosensory evoked cortical potential amplitudes were reduced following crush or compression injury to the inferior rectal nerve in an animal model of neurogenic FI, leading the authors to conclude that alteration in cortical awareness may be the result of processing modification at a central and not peripheral level .…”

Microstructural white matter brain abnormalities in patients with idiopathic fecal incontinence

“…All subjects were recruited from the Department of Surgery, Aarhus University Hospital, as part of a series of studies examining the afferent sensory pathways of the ano‐rectum in IFI patients. Data on the latencies of the cortical potentials evoked by rectal stimuli have been part of previous publications …”

“…Independent t tests were performed to determine whether IFI patients and healthy controls differed in age, body mass index (BMI), Wexner fecal incontinence scores and CEP latency measurements. CEP data were extracted from our previous study . Because of our previous findings on CEP changes in IFI patients, we investigated whether prolonged latencies were associated with structural brain changes.…”

“…It has been proposed that damage to afferent fibers during childbirth leads to the loss of cortical awareness of the pelvic floor. Congruently, several studies have concluded that the conduction of stimuli from the ano‐rectum to the brain is abnormal both in animal models of FI and in humans with IFI …”

“…Recently, our group found that latencies of cortical evoked potentials (CEPs) from rectal stimuli were prolonged in IFI patients . Furthermore, spectral analysis of CEPs from stimuli of the anal canal showed reduced amplitudes of high frequency bands .…”