Effects Of Sacral Nerve Stimulation Research Articles

Effects of Sacral Nerve Stimulation on Neuronal Nitric Oxide Synthase in the Colon and Sacral Cord of Rats With Defecation Disorder After Spinal Cord Injury

This study aimed to determine the effects of sacral nerve electrical stimulation (SNS) on neuronal nitric oxide synthase (nNOS) in the colon and sacral cord of rats with defecation disorder after spinal cord injury (SCI). Rats with severe SCI (T10) were used as models and randomly divided into an SCI group and an SNS group. After 14 days of treatment, the intestinal transport function was assessed. Finally, the differences in nNOS immunoreactive cells, protein levels, nNOS mRNA, and NO content in the colon and sacral cord tissues were estimated using immunohistochemistry, Western blot, real-time polymerase chain reaction, and nitrate reductase method. The intestinal transport function of the SNS group was superior to that of the SCI group (P < 0.05). The average optical density of nNOS immunoreactive positive cells in the SCI group were significantly increased compared with those in the sham group. The content of NO of the SCI group significant increased compared with those of the sham group and the SNS group (both P < 0.01). The nNOS mRNA and protein expression was higher in the SCI group than in the sham group (P < 0.01), while that in the SNS group was significantly lower than that in the SCI group. SNS could reduce nNOS expression in the colon and sacral cord of SCI rats. This reduction may be an important neuromodulation mechanism for SNS to improve defecation reflex and promote the recovery of intestinal transit function.

Neuro-Immune Modulation Effects of Sacral Nerve Stimulation for Visceral Hypersensitivity in Rats.

Background: Visceral hypersensitivity (VH) is one of the underlying pathophysiologies of irritable bowel syndrome. Mast cell overactivation has been found to be one of the main causes of VH. We investigated the effects and mechanisms of actions of sacral nerve stimulation (SNS) on visceral pain in a rodent model of VH.Methods: The VH was established by an intrarectal infusion of AA in 10-day-old pups. Rats were chronically implanted with electrodes for SNS and recording electromyogram (EMG) and electrocardiogram. The acute study was performed in 2-randomized sessions with SNS (14 Hz, 330 μs, 40% motor threshold or MT, 30 min) or sham-SNS. Later on, rats were randomized into SNS/sham-SNS groups and a chronic study was performed with 2 h-daily SNS or sham-SNS for 21 days. Visceromotor reflexes were assessed by abdominal EMG and withdrawal reflex (AWR). Colon tissues were collected to study colonic acetylcholine (ACh), the enteric neurons (ChAT, nNOS, and PGP9.5), mast cells activity [Tryptase, prostaglandins E2 (PGE2), and cyclooxygenases-2 (COX2)] and pain markers [nerve growth factor (NGF) and Sub-P].Key Results: Sacral nerve stimulation significantly improved visceromotor reflexes assessed by the EMG and AWR, compared with sham-SNS. SNS normalized the protein expressions of ChAT and nNOS and regulated mast cells activity by downregulating Tryptase, COX2, and PGE2. Neonatal AA administration upregulated NGF and Sub-P; chronic SNS significantly decreased these pain biomarkers. Concurrently, chronic SNS increased ACh in colon tissues and vagal efferent activity.Conclusions: Sacral nerve stimulation reduces VH in rats and this ameliorating effect might be attributed to the suppression of mast cell overactivation in the colon tissue via the modulation of autonomic nervous system functions.

Anti-inflammatory effects of sacral nerve stimulation: a novel spinal afferent and vagal efferent pathway.

Sacral nerve stimulation (SNS) was reported to improve 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. The aim of this study was to investigate whether the SNS anti-inflammatory effect is mediated via the local sacral splanchnic nerve or the spinal afferent-vagal efferent-colon pathway. Under general anesthesia, rats were administrated with TNBS intrarectally, and bipolar SNS electrodes were implanted unilaterally at S3. The sacral and vagal nerves were severed at different locations for the assessment of the neural pathway. SNS for 10 days improved colonic inflammation only in groups with intact afferent sacral nerve and vagus efferent nerve. SNS markedly increased acetylcholine and anti-inflammatory cytokines (IL-10) and decreased myeloperoxidase and proinflammatory cytokines (IL-2, IL-17A, and TNF-α) in colon tissues. SNS increased the number of c-fos-positive cells in the brain stem and normalized vagal activity measured by spectral analysis of heart rate variability. SNS exerts an anti-inflammatory effect on TNBS-induced colitis by enhancing vagal activity mediated mainly via the spinal afferent-brain stem-vagal efferent-colon pathway.NEW & NOTEWORTHY Our findings support that there is a possible sacral afferent-vagal efferent pathway that can transmit sacral nerve stimulation to the colon tissue. Sacral nerve stimulation can be carried out by spinal cord afferent to the brain stem and then by the vagal nerve (efferent) to the target organ.

Sa1312 – Ameliorating Effects of Sacral Nerve Stimulation and Mechanisms Involving Nerve Growth Factor and Trpv1 in a Rodent Model of Visceral Hypersensitivity

Sa1312 – Ameliorating Effects of Sacral Nerve Stimulation and Mechanisms Involving Nerve Growth Factor and Trpv1 in a Rodent Model of Visceral Hypersensitivity

Su1621 – Ameliorating Effects of Sacral Nerve Stimulation on Pacemaking Activities of the Stomach and Duodenum: Evidence of a Retrogreade Spinal-Vagal Pathway

Su1621 – Ameliorating Effects of Sacral Nerve Stimulation on Pacemaking Activities of the Stomach and Duodenum: Evidence of a Retrogreade Spinal-Vagal Pathway

1048 - Centrally Mediated Vagal Efferent Pathway Involved in Anti-Inflammatory Effects of Sacral Nerve Stimulation

1048 - Centrally Mediated Vagal Efferent Pathway Involved in Anti-Inflammatory Effects of Sacral Nerve Stimulation

Does Sacral Nerve Stimulation Improve Continence Through Enhanced Sensitivity of the Anal Canal? A Pilot Study.

It has been suggested that the effects of sacral nerve stimulation against fecal incontinence involve neuromodulation at spinal or supraspinal levels. This study aims to investigate the afferent sensory pathways from the anorectum before and during sacral nerve stimulation. This is an explorative study. Fifteen women with idiopathic fecal incontinence (mean age, 58 ± 12.2 years) were selected. Cortical evoked potentials were recorded during repeated rapid balloon distension of the rectum and the anal canal both before and during temporary sacral nerve stimulation. Stimuli applied were individualized according to the subjective urge to defecate. The main outcomes measured were 1) stimulus intensity, 2) latencies and amplitudes of cortical evoked potentials, and 3) spectral content in predefined frequency bands of cortical evoked potentials. The median Wexner fecal incontinence score improved from 15.5 ± 3.6 before to 6.7 ± 5 during sacral nerve stimulation (p < 0.001). Sacral nerve stimulation did not affect the threshold for urge to defecate during rectal distension (p = 0.64) but reduced the threshold from stimulation of the anal canal by 50% (p = 0.03). No statistically significant differences were found in latencies, amplitudes, or spectral analysis. This is a pilot study of limited size. In patients with idiopathic fecal incontinence, sacral nerve stimulation reduced the threshold for urge to defecate elicited from the anal canal, whereas supraspinal responses remained unaltered. This may suggest that sacral nerve stimulation, at least in part, acts via somatic afferent fibers enhancing anal sensation.

Effects of sacral nerve stimulation with acupuncture on gut transit time and c-kit expression in colon of rats with slow transit constipation.

Sacral nerve stimulation (SNS) is an alternative surgical approach to alleviate fecal incontinence and constipation. This study aimed to explore the effects and underlying mechanisms of SNS with acupuncture on gut transit time and colon c-kit protein expression in rats with slow transit constipation (STC). Fifty Sprague-Dawley rats were randomly divided into five groups: blank control, SNS, Mosapride, sham SNS, and STC model control group. The STC model was established by subcutaneous injection of morphine. Each group was treated over a 15-day period. Gut transit time was measured 1 day before the treatment started and after 5, 10, and 15 days of treatment. After the 15-day treatment, animals were sacrificed and colonic tissues were collected for analysis of c-kit protein expression, using western blot analysis. We found significant differences in gut transit time in the SNS group compared with the Mosapride group after 5 (P = 0.001) and 10 (P = 0.004) days of treatment. After 15 days of treatment, there were no differences in gut transit time among the SNS, Mosapride, and blank control groups. However, significant differences were observed when comparing the SNS and Mosapride groups with the STC model and sham SNS groups. A decreased c-kit protein expression was observed in the STC model control, sham SNS, and Mosapride groups, compared with the SNS group (P = 0.001). Our data indicate that SNS can decrease gut transit time and increase the expression of c-kit protein in rats with STC to improve colon transit function.

Effects of sacral nerve stimulation on postpartum urinary retention-related changes in rat bladder

ObjectiveTo examine the effect of sacral nerve stimulation (SNS) on the urodynamic function and molecular structure of bladders in rats following acute urinary retention (AUR) after parturition. Material and methodsThirty primiparous rats were divided into three groups: postpartum, postpartum+AUR, and postpartum+AUR+SNS. AUR was achieved by clamping the distal urethra of a rat for 60 minutes. The postpartum+AUR+SNS group received electrical stimulation 60 minutes daily for 3 days after AUR. In addition to cystometric studies and external urethral sphincter electromyography, the expression of caveolins and nerve growth factor (NGF) and caveolae number in bladder muscle were analyzed. ResultsThe postpartum+AUR group has significantly greater residual volume than the postpartum group, but the residual volume decreased significantly after SNS treatment. The postpartum+AUR group had significantly lower peak voiding pressure, a longer bursting period and lower amplitude of electromyograms of external urethral sphincter activity than the postpartum and postpartum+AUR+SNS groups. The postpartum+AUR rats had higher NGF expression, lower caveolin-1 expression, and fewer caveolae in bladder muscle compared with the postpartum rats. Conversely, the caveolin-1 expression and caveolae number increased, and the NGF expression decreased after SNS treatment. ConclusionBladder dysfunction after parturition in a rat model caused by AUR may be restored to the non-AUR structural and functional level after SNS treatment.

The effects of sacral nerve stimulation on continence are temporarily maintained after turning the stimulator off

Sacral nerve stimulation is an effective treatment for urinary and faecal incontinence even though its mechanism of action is uncertain. Central nervous system involvement by 'setting-up' neurological mechanisms appointed to control pelvic function has been hypothesized. The study aimed to evaluate whether the effects of long-term sacral nerve stimulation are memorized and therefore maintained after switching off the stimulator. Patients having sacral nerve stimulation for faecal and/or urinary incontinence for at least 1year had the stimulator turned off and the results monitored. Data recorded with the stimulator off were compared with post-implant data. If symptoms recurred the stimulator was switched back on. Nineteen patients entered the study. Fourteen had faecal and/or urinary incontinence and five had faecal incontinence alone. The symptoms were assessed by means of a bowel function diary and dedicated questionnaire. In 10 patients symptoms recurred at different intervals after a median off period of 3.4months with a probability of symptom relapse of 55%. The Fecal Incontinence Quality of Life (FIQL) score did not show any significant difference in nine patients with the stimulator off for at least 1year. No factors predictive of symptom recurrence were identified although an idiopathic aetiology, severity of disease and urinary incontinence had higher hazard ratios. During the off period, none of the scores and episodes of incontinence showed significant changes compared with the on period. The effects of sacral nerve stimulation on faecal and urinary incontinence were maintained in about half of patients after switching the stimulator off, but in some symptoms returned after different periods of time. The data shed new light on possible effects of sacral nerve stimulation on brain neuroplasticity in the control of continence.

Tu1328 The Effects of Sacral Nerve Stimulation on Fecal/Urinary Incontinence are Maintained After Switching the Stimulator off

Tu1328 The Effects of Sacral Nerve Stimulation on Fecal/Urinary Incontinence are Maintained After Switching the Stimulator off

Sacral Nerve Stimulation in Patients with Severe Constipation

Constipation is frequently a multifactorial disease. This study was designed to evaluate the potential effects of sacral nerve stimulation for patients suffering from severe chronic constipation. Nineteen patients suffering from pathologic colonic transit time or rectal outlet obstruction were included. Only patients with severe rectal outlet obstruction who needed digital manipulation for defecation or patients suffering from pathologic colonic transit constipation with less than two bowel movements per week were regarded as candidates. A temporary stimulation lead was implanted into the sacral foramen that showed the best muscular response. After an evaluation period, the stimulation electrode was removed. An improvement in constipation (more than 2 bowel movements per week or defecation without digital manipulation, respectively) during the test stimulation, as well as a recurrence of prestimulation constipation symptoms during the following surveillance period of three weeks were prerequisites for implanting the permanent sacral nerve stimulating system. All of the patients showed a positive motor response to acute needle stimulation. After the evaluation period, eight patients (42 percent) reported an improvement of constipation, and permanent systems were implanted successfully. During the median follow-up of 11 (range, 2-20) months, a significant improvement in the Wexner constipation score was observed compared with the preoperative baseline level (baseline: median: 23, range, 18-27; 12 months after implantation: median, 8, range, 4-13). After successful sacral nerve stimulation, patients also showed a significant improvement in their quality of life. Patients suffering from severe constipation are a new challenge for sacral nerve stimulation but further research on pelvic floor function is needed.