Does magnetic stimulation of sacral nerve roots modify colonic motility? Results of a randomized double‐blind sham‐controlled study

Abstract

Although sacral nerve root stimulation (SNS) can result in a symptomatic improvement of faecal incontinence, the mechanism of action remains unknown. The aim of this study was to assess whether short-term magnetic SNS can inhibit pharmacologically induced propulsive colonic contractions. Twelve healthy volunteers (median age: 43.5 years old) were studied on two separate occasions and randomized into either active (15 Hz, 100% output intensity for 5 s min(-1) for 30 min) or sham rapid rate lumbosacral magnetic stimulation (rLSMS). Colorectal motility was recorded with a manometric catheter located at the most proximal transducer in the left colon and the most distal, in the rectum. Colonic contractions were provoked by instilling Bisacodyl. The effects of rLSMS on colonic, sigmoid and rectal contractions were monitored and recorded after Bisacodyl instillation. The appearance of high-amplitude contractions propagated or not (HAC/HAPC) provoked by Bisacodyl instillation was significantly delayed during active compared to sham stimulation (P = 0.03). There was no difference in the characteristics of HAC/HAPC (i.e. frequency, amplitude, duration, velocity of propagation) or the motility index with active or sham stimulation. The perception of urgency tended to be decreased with rLSMS following Bisacodyl instillation. The catheter was expulsed within a median of 16.5 min (range 8-39) after Bisacodyl administration during active stimulation compared to 14 min (range 5-40) during sham stimulation (P = 0.03). This study suggests that rLSMS could delay the appearance of the first Bisacodyl-induced colonic contractions.

Acute sacral nerve stimulation reduces visceral mechanosensitivity in Rat through spinal opioid pathway

“…Therefore, a hypothetical drop in colonic motor activity induced by SNS would probably not have been accurately detected in our model. In fact, we previously showed that magnetic sacral root stimulation modified the delay of appearance of bisacodyl‐induced contractions in healthy volunteers . This was further corroborated by Michelsen et al ., who showed using colonic scintigraphy that SNS reduced anterograde transport from the ascending colon and increased retrograde transport from the descending colon .…”

Predictive factors for successful sacral nerve stimulation in the treatment of faecal incontinence: results of trial stimulation in 200 patients

“…Indeed, the Bristol stool scale has shown that stool consistency may become more solid after permanent implantation [18]. In addition, several recent studies have evaluated the effect of SNS on colonic motility [19–21]. Gallas et al.…”

Neurostimulation for Neurogenic Bowel Dysfunction

“…A randomized study compared magnetic stimulation and sham stimulation in healthy able subjects [67]. The appearance of high-pressure contractions and high pressure propagated contractions provoked by Bisacodyl instillation was significantly delayed during stimulation.…”