Sacral Magnetic Stimulation Research Articles

Peripheral Sacral Magnetic Stimulation in Patients with Idiopathic Overactive Bladder: a Single Blind Prospective Randomized Comparative Clinical Study

INTRODUCTION. Overactive bladder (OAB) is a symptom complex that includes urgency, frequent urination, imperative urinary incontinence and nocturia. The idiopathic form of OAB is associated with dysfunction of sensory signal transmission at the level of the peripheral and central nervous system, which leads to bladder hypersensitivity. The low level of patients’ compliance to OAB drug therapy and the high level of refusal to take drugs emphasize the urgency of finding new effective methods of influencing the lower urinary tract. Magnetic stimulation (MS) is a non-drug treatment for lower urinary tract dysfunction.
 AIM. To study the efficacy and safety of the sacral MS method in women with idiopathic detrusor overactivity (DO) and OAB symptoms.
 MATERIALS AND METHODS. A single blind prospective randomized comparative study included 55 female patients with urodynamically confirmed idiopathic DO. The patients were divided by simple randomization into the main group (n = 29), which received MS 3 times a week for 5 weeks with a frequency of 5 Hz per sacral root area (S2–S4), and the placebo group (n = 26), in which sham stimulation was performed.
 RESULTS AND DISCUSSION. The study revealed that sacral MS is reliably effective against the clinical symptoms of OAB in idiopathic DO. The dynamics of clinical symptoms is confirmed by changes in urodynamic parameters. The effect of sacral MS significantly exceeds placebo. MS is a safe procedure and is well tolerated by patients.
 CONCLUSION. The sacral MS method, the effectiveness of which has been proven in comparison with placebo, is recommended to be included in the treatment regimen of patients with idiopathic OAB. The mechanism of action of sacral MS is associated with the activation of sympathetic and inhibition of parasympathetic influences, as well as changes in supraspinal control and cerebral activity.

Sacral nerve magnetic stimulation combined with rehabilitation training in the treatment of primary nocturnal enuresis in children

Objective: To explore the clinical value of sacral magnetic stimulation (SMS) combined with rehabilitation training in the treatment of primary nocturnal enuresis (PNE) in children. Methods: The clinical data of 57 children with PNE admitted to the Department of Rehabilitation Xuzhou Rehabilitation Hospital, Xuzhou Central Hospital and Xuzhou Children's Hospital from October 2019 to September 2020 were collected and analyzed. The children were divided prospectively into observation group and control group by using random number table method. Bladder function training, awakening training and life and psychological intervention were performed in both groups, while the observation group was treated with SMS based on the above treatment methods. Before and after treatment, the degree and the frequency of enuresis (normal, mild, moderate, severe), therapeutic evaluation and bladder volume were compared. Chi-square test and T test were used for comparison between the two groups. Results: Finally, 28 cases in the observation group and 29 cases in the control group were included. There was no significant difference in age, sex, degree and of frequency enuresis of children between the two groups (all P>0.05).The degree of enuresis in the observation group after 1 month of treatment was better than that in the control group (12 vs. 7 cases, 8 vs. 8 cases, 5 vs. 9 cases, 3 vs. 5 cases, χ2=-2.269, P=0.030). Enuresis times in observation group was lower than that in the control group [(4.2±1.8) vs. (8.1±2.0), t=4.475, P<0.01). The total effective rate and bladder capacity of efficacy evaluation were higher than those of control group [82%(23/28) vs. 48%(14/29), (225±25) vs. (199±21) ml, Z=11.238, t=-2.249, both P<0.05]. Conclusions: SMS is an effective method for the treatment of PNE in children, which can reduce the degree and frequency of enuresis in children, increase the bladder volume and improve the total effective rate of treatment. It is worthy of clinical promotion and application.

Assessments of Pudendal Motor and Sensory Nerves in Patients with or without Fecal Incontinence after Low Anterior Resection for Lower Rectal Cancer

Background: To clarify the pudendal motor (PMN) and sensory (PSN) nerves play in preventing fecal incontinence (FI) after low anterior resection (LAR) for lower rectal cancer, the PMN and PSN functions were studied. Methods: Sixty patients were divided into groups A (n = 20, FI) and B (n = 40, continence). These were compared with group C (n = 30, control subjects). PMN latency (PMNL) (right, left, and posterior sides of the anal canal) was studied by sacral magnetic stimulation. Anal mucosal electric sensitivity (AMES) was measured at the lower, dentate line (DL), and upper zones. Results: The distance of anastomosis from anal verge (DAAV) in group A was significantly shorter than in group B (p value p value p value p value Conclusion: FI after LAR with a short DAAV may lead to external anal sphincter dysfunction due to damage of both PMN and PSN.

The effect of cortical versus sacral repetitive magnetic stimulation on lower urinary tract dysfunction in patients with multiple sclerosis.

75% of multiple sclerosis (MS) patients have lower urinary tract symptoms. Moreover, up to 80% of asymptomatic patients show abnormalities on urodynamic examination. The objective of this study is to assess the effect of repetitive magnetic stimulation on the motor cortex versus sacral roots in MS patients with lower urinary tract dysfunction (LUTD). 40 MS patients with LUTD were divided according to urodynamic studies (UDS) into two groups (20 patients each): Group A (overactive bladder) and Group B (underactive bladder). Each group was further subdivided into Subgroup (A-I) and (B-I) which received cortical magnetic stimulation and Subgroup (A-II) and (B-II) which received sacral magnetic stimulation. UDS, pelvic ultrasound as well as Incontinence Quality of Life (I-QOL) questionnaire were compared before and after magnetic stimulation sessions in each group as well as between groups. UDS showed significant reduction in bladder capacity, improvement in bladder contractility in all groups and subgroups. Moreover, it showed improvement of urine flow rate only in Group B. Reduction of post-void residual urine was noted in all subgroups except in (Group A-II). I-QOL questionnaire showed improvement in patients with underactive bladder only. Intergroup comparison between A and B showed no difference. Cortical as well as sacral magnetic stimulation showed significant effect on lower urinary tract dysfunction that led to improvement in symptoms in MS patients with underactive bladder, rather than those with overactive bladder.

O11 Motor cortex versus sacral magnetic stimulation in lower urinary tract dysfunction in multiple sclerosis

Background Lower urinary tract dysfunction (LUTD) occurs in more than 75% of patients with Multiple Sclerosis (MS).There are few studies investigating effect of repetitive magnetic stimulation on LUTD in MS patients. Aim of the work Assess the effect of repetitive magnetic stimulation on the sacral roots versus motor cortex in MS patients with LUTD. Methods 40 MS patients with LUTD were divided into two groups (20 patients each); Group A (overactive bladder) and Group B (underactive bladder) according to urinary bladder dysfunction. Then, each group was further subdivided into Subgroup (I) received cortical magnetic stimulation and Subgroup (II) received sacral magnetic stimulation. Results In Group A (overactive bladder) patients; patients who received cortical magnetic stimulation showed a statistically significant reduction in maximum cystometric capacity (MCC) and post-void residual urine (PVR) together with a significant increase in maximum flow rate (Qmax). There was no statistically significant difference in I-QOL questionnaire score and detrusor pressure at maximum flow rate (Pdet@Qmax). Group (A) patients who received sacral magnetic stimulation showed a statistically significant reduction in MCC and Qmax. While there was no statistically significant difference in I-QOL questionnaire score, PVR or Pdet@Qmax. In Group B (underactive bladder) patients; patients who received cortical and patients received sacral magnetic stimulation showed a statistically significant reduction in I-QOL questionnaire score, post-void residual urine (PVR) and maximum cystometric capacity (MCC), with a significant increase in detrusor pressure at maximum flow rate (Pdet@Qmax) and maximum flow rate (Qmax). Conclusion 5 Hz sacral as well as cortical repetitive magnetic stimulation caused a significant decrease in MCC and increase in Pdet@Qmax which is expected to improve the underactive bladder symptoms, while it worsens the overactive bladder symptoms.

Long-Term Sacral Magnetic Stimulation for Refractory Stress Urinary Incontinence

ObjectiveTo evaluate the effects of sacral magnetic stimulation (SMS) on functional and urodynamic improvement in patients with refractory stress urinary incontinence (SUI). DesignA sham-controlled, double-blind, parallel study design with a 4.5-month follow-up. SettingA tertiary hospital. ParticipantsWomen (age, 45–75y) with SUI refractory to first-line management (N=34) were allocated to either an experimental (n=20) group or a sham (n=14) group. InterventionsThe SMS protocol consisted of 5-Hz, 20-minute treatments administered over the bilateral third sacral roots, with the intensity set at approximately 70% of the maximal output, for 12 consecutive weekdays. Main Outcome MeasuresUrodynamic assessments and 2 life stress questionnaires, namely, the Urge-Urinary Distress Inventory (U-UDI) and the Overactive Bladder Questionnaire (OAB-q), were administered pre- and post-SMS intervention. We administered the U-UDI (primary outcome measure) and the OAB-q at 3-week intervals during the follow-up period until 18 weeks after the final intervention. ResultsThe experimental group exhibited significant improvements in both U-UDI and OAB-q scores postintervention (P=.011–.014) and at follow-up visits (P<.001–.007) compared with the sham group. In addition, significant increases in bladder capacity, urethral functional length, and the pressure transmission ratio (P=.009–.033) were noted postintervention. Multivariate regression analysis revealed that patients with more severe symptoms benefited more from SMS. A poorer baseline U-UDI score and a shorter urethral functional length were associated with a greater response to SMS. ConclusionsOur observations of a greater response to SMS in patients with more severe SUI than in those with mild symptoms, as well as the long-term benefits of the treatment, confirm the efficacy of SMS in treating SUI.

Translumbar and transsacral magnetic neurostimulation for the assessment of neuropathy in fecal incontinence.

Neurologic dysfunction causes fecal incontinence, but current techniques for its assessment are limited and controversial. The purpose of this work was to investigate spino-rectal and spino-anal motor-evoked potentials simultaneously using lumbar and sacral magnetic stimulation in subjects with fecal incontinence and healthy subjects and to compare motor-evoked potentials and pudendal nerve terminal motor latency in subjects with fecal incontinence. This was a prospective, observational study. The study took place in 2 tertiary care centers. Subjects included adults with fecal incontinence and healthy subjects. Translumbar and transsacral magnetic stimulations were performed bilaterally by applying a magnetic coil to the lumbar and sacral regions in 50 subjects with fecal incontinence (1 or more episodes per week) and 20 healthy subjects. Both motor-evoked potentials and pudendal nerve terminal motor latency were assessed in 30 subjects with fecal incontinence. Stimulation-induced, motor-evoked potentials were recorded simultaneously from the rectum and anus with 2 pairs of bipolar ring electrodes. Latency and amplitude of motor-evoked potentials after lumbosacral magnetic stimulation and agreement with pudendal nerve terminal motor latency were measured. When compared with control subjects, 1 or more lumbo-anal, lumbo-rectal, sacro-anal, or sacro-rectal motor-evoked potentials were significantly prolonged (p < 0.01) and were abnormal in 44 (88%) of 50 subjects with fecal incontinence. Positive agreement between abnormal motor-evoked potentials and pudendal nerve terminal motor latency was 63%, whereas negative agreement was 13%. Motor-evoked potentials were abnormal in more (p < 0.05) subjects with fecal incontinence than pudendal nerve terminal motor latency, in 26 (87%) of 30 versus 19 (63%) of 30, and in 24% of subjects with normal pudendal nerve terminal motor latency. There were no adverse events. Anal EMG was not performed. Translumbar and transsacral magnetic stimulation-induced, motor-evoked potentials provide objective evidence for rectal or anal neuropathy in subjects with fecal incontinence and could be useful. The test was superior to pudendal nerve terminal motor latency and appears to be safe and well tolerated.

Effects of neuromodulation with sacral magnetic stimulation for intractable bowel or bladder dysfunction in postoperative patients with anorectal malformation: a preliminary report

The effects of neuromodulation with sacral magnetic stimulation (SMS) were examined in postoperative patients with bowel or bladder dysfunction. SMS was performed at the S3 level using a MagPro® instrument (Medtronic Inc., USA) while the patients were under light sedation. One treatment course consisted of stimulation delivered at 15 Hz for 5 s, 10 times over an interval of 1 min. Three patients with bladder or bowel dysfunction refractory to conservative treatment were examined. Case 1 is a 7-year-old male with a rectourethral fistula. This patient developed a hyperdynamic bladder after a laparoscopic pull-through operation at the age of 7 months. The administration of an anticholinergic agent slightly improved the condition. SMS was started at the age of 4 years with one trial each year. A marked expansion of bladder volume from 20 ml before trial to 120 ml after the third trial was obtained. Case 2 (a 4-year old female with a recto-vaginal fistula) and Case 3 (a 8-year-old female with an ano-vestibular fistula) showed severe constipation after radical surgery during infancy. Case 2 needed appendicostomy. After SMS, bowel movements could become controllable with enemas. No adverse effects were observed for any of the three cases. These results suggest that SMS might be a useful modality to improve postoperative bowel or bladder dysfunction.

Effect of sacral magnetic stimulation on the anorectal manometric activity: a new modality for examining sacro-rectoanal interaction

We examined the interaction between the sacral neural system and the anorectal activity using a technique comprising repetitive magnetic stimulation. Thirteen control children without any bowel dysmotility (age range; 3 month old to 15 year old), 20 patients with chronic constipation (1 month old to 14 year old), and nine pre-operative patients with Hirschsprung's disease (1 month old to 6 year old) were examined. Magnetic stimulation was applied at the S3 level using the MagPro (Medtronic) device while simultaneously performing manometric recordings of the anorectal activity. In the 13 controls and the 20 patients with chronic constipation, the rectoanal reflex was demonstrated by balloon rectal dilatation. The sphincter response to magnetic stimulation was biphasic in the controls, consisting of an initial rise followed by a decrease in the sphincter pressure, while it varied among the patients with chronic constipation including a biphasic response in 16 patients, no response in three patients, and only a transient rise in pressure in one patient. In nine pre-operative patients with Hirschsprung's disease, no rectoanal reflex was observed, however, the sphincter pressure increased due to magnetic stimulation in six patients, while three patients exhibited no recordable responses. These results suggest that the repetitive magnetic stimulation technique is a valuable modality for investigating the neural interaction between the sacral nervous system and the anorectum.

Neurophysiological testing in anorectal disorders

The neurophysiological techniques currently available to evaluate anorectal disorders include concentric needle electromyography (EMG) of the external anal sphincter, anal nerve terminal motor latency (TML) measurement in response to transrectal electrical stimulation or sacral magnetic stimulation, motor evoked potentials (MEPs) of the anal sphincter to transcranial magnetic cortical stimulation, cortical recording of somatosensory evoked potentials (SEPs) to anal nerve stimulation, quantification of electrical or thermal sensory thresholds (QSTs) within the anal canal, sacral anal reflex (SAR) latency measurement in response to pudendal nerve or perianal stimulation, and perianal recording of sympathetic skin responses (SSRs). In most cases, a comprehensive approach using several tests is helpful for diagnosis: needle EMG signs of sphincter denervation or prolonged TML give evidence for anal motor nerve lesion; SEP/QST or SSR abnormalities can suggest sensory or autonomic neuropathy; and in the absence of peripheral nerve disorder, MEPs, SEPs, SSRs, and SARs can assist in demonstrating and localizing spinal or supraspinal disease. Such techniques are complementary to other methods of investigation, such as pelvic floor imaging and anorectal manometry, to establish the diagnosis and guide therapeutic management of neurogenic anorectal disorders.

Sacral magnetic stimulation in non‐inflammatory chronic pelvic pain syndrome

To prospectively evaluate sacral magnetic high-frequency stimulation as a treatment option for patients with non-inflammatory chronic pelvic pain syndrome (CPPS, category IIIB). Fourteen men with CPPS IIIB were treated with high-frequency sacral magnetic stimulation, with 10 treatment sessions once a week for 30 min at a frequency of 50 Hz. The National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) and quality-of-life index were determined before and after treatment. All patients tolerated the stimulation well and 12 of 14 reported agreeable sensations during stimulation. There were no complications; only one patient did not complete the treatment course. The mean (range) total NIH-CPSI score did not change with treatment, at 27 (18-38) before and 27 (4-40) after treatment. Moreover, there was no sustained effect on the mean scores for pain, micturition complaints or quality of life. High-frequency sacral magnetic stimulation in patients with CPPS IIIB only reduces pain during stimulation, with no sustained relief of symptoms. Therefore, intermittent sacral magnetic stimulation cannot be recommended as a treatment option for CPPS IIIB.

Towards a better understanding of involuntary detrusor activity

There is a wide spectrum of topics covered in this section. The ever-present problem of nocturia is further explored by authors from Sweden, with interesting conclusions. In addition, several papers describe various issues relating to the surgical correction of stress urinary incontinence. Finally, authors from Switzerland describe their use of sacral magnetic stimulation in non-inflammatory chronic pelvic pain syndrome. To compare the measured variables of involuntary detrusor activity (IDA) during ambulatory cystometry (AC) in women with and with no overactive bladder symptoms, and to evaluate the correlation between these variables and symptom severity. In all, 61 symptomatic and 39 asymptomatic women completed the Bristol Female Lower Urinary Tract Symptoms Questionnaire (BFLUTS-Q) and underwent AC. Measured variables of IDA (amplitude, duration, bladder volume and symptoms) were compared in the two cohorts. IDA was detected in 47 of 61 symptomatic women (77%) and in 17 of 36 (47%) controls (P < or = 0.01). The maximum IDA (defined as the highest amplitude contraction in any fill-void cycle) occurred at significantly lower volumes (328 vs 450 mL, P < or = 0.05), was of higher amplitude (26 vs 12 cm H(2)O, P = 0.14) and longer duration (83 vs 14 s, P < or = 0.05) in symptomatic women than in controls. There was coincident incontinence in 22 (36%) symptomatic women and no controls (P < or = 0.01). Discriminatory levels for clinically relevant IDA were established, and when applied retrospectively, classified 35 of 61 symptomatic women (55%) and one control (3%) as having such IDA. The correlation between symptom severity (measured by the BFLUTS-Q) and urodynamics was higher when these criteria were applied (r = 0.52 vs 0.38, P < or = 0.01). There are quantifiable differences between IDA found during AC in symptomatic and asymptomatic women. The measured variables of IDA may be useful to determine its clinical relevance, which may be indicated by contractions associated with leakage or contractions of >30 s occurring at bladder volumes of <300 mL.

The effect of tamsulosin on the resting tone and the contractile behaviour of the female urethra: a functional urodynamic study in healthy women.

The aim of this functional urodynamic experiment was to study the effect of the selective alpha1(A)-blocker tamsulosin on the urethral pressure in healthy human females and assessed first the resting urethral pressure and second the urethral contractility in response to magnetic stimulation of the sacral roots. 11 healthy female subjects gave their written informed consent and were included. A microtip pressure transducer catheter was inserted into the bladder and three baseline urethral pressure profiles were obtained. Another three urethral pressure profiles were recorded while magnetic single pulse stimulation of the sacral roots was performed above the motor threshold of the pelvic floor to evoke reproducible urethral contractions. Then the subjects received 0.4 mg of tamsulosin and the entire protocol was repeated 6 hours after drug administration. Cardiovascular monitoring was obtained during the baseline and follow-up measurements. Mean and maximal urethral pressure values calculated over the entire urethra, mean pressure values calculated over the proximal, middle and distal third of the urethra and the pressure amplitudes to magnetic stimulation at baseline were statistically compared to the follow-up measurements with tamsulosin. The oral administration of tamsulosin did not change the systemic blood pressure, but did significantly reduce the mean and maximal urethral pressure acquired over the entire urethra. When the proximal, middle and distal third of the urethra were analysed separately, there was a significant pressure reduction in all three segments. Amplitudes of the urethral contractions evoked by sacral magnetic stimulation remained unchanged after tamsulosin. These data show a significant relaxing effect of tamsulosin on the resting urethral tone in healthy females in vivo. These results may suggest tamsulosin as a new pharmacological approach to treat urinary retention due to overactive or non-relaxing urethra in women.

417 Pelvic floor reflex responses to repeated electrical dorsal penile nerve and sacral magnetic stimulation

417 Pelvic floor reflex responses to repeated electrical dorsal penile nerve and sacral magnetic stimulation

Sacral magnetic stimulation for pain relief from pudendal neuralgia and sciatica.

Magnetic stimulation of the sacral nerve roots is used for neurologic examination. However, no one has reported therapeutic efficacy of pain relief from pudendal neuralgia with sacral magnetic stimulation. Five patients with pudendal neuralgia or sciatica received 30 to 50 pulsed magnetic stimuli of the sacral nerve roots. The median age of the patients was 59 (range, 28-69) years; there were 3 females. Sacral magnetic stimulation immediately eliminated the pain. The pain relief lasted between 30 minutes and 56 days (median, 24 hours). Adverse effects were not observed. This pilot study indicates that magnetic stimulation of the sacral nerve roots may be a promising therapeutic modality for pain relief from pudendal neuralgia and sciatica. Further studies should be performed to determine the appropriate intensity and frequency, as well as the utility of a second course, of magnetic stimulation treatment.

Sacral magnetic stimulation in puborectalis paradoxical syndrome.

Our earlier studies have demonstrated that sacral magnetic stimulation (MS) in the canine model, in healthy volunteers and in constipated subjects effected rectal pressure rise, decline of the rectal neck (anal canal) pressure as well as rectal evacuation. Based on these results, we studied the effect of sacral MS on defecation in patients with puborectalis paradoxical syndrome (PPS). Eleven subjects (8 women, 3 men; age 36-53 years) with PPS were enrolled in the study. The magnetic coil was placed on the back with its center located between L4 and L5. Stimulation parameters were set at 70% of maximum intensity, 40 Hz frequency and 2-second burst length with 2 seconds off. During MS, the rectal neck and gastric (intra-abdominal) pressures were measured. The procedure was performed in the empty and in the full rectum using the balloon expulsion test in the latter. MS of the empty and balloon-filled rectum effected rise of the rectal pressure (p < 0.001), decline of the rectal neck pressure (p > 0.001) and no significant change of the intragastric pressure (p > 0.05). The balloon was expelled to the exterior in all the patients. Sacral MS succeeded in dispelling to the exterior the water-filled rectal balloon. The method is simple, easy, non-invasive, non-radiologic and can be performed on an outpatient basis for the treatment of PPS.

Variations in motor evoked potential latencies in the anal sphincter system with sacral magnetic stimulation.

The anal sphincter system of the skeletal musculature consists of various parts but functions as a single unit. The motor latencies measured at the puborectalis, deep external anal sphincter, superficial external anal sphincter, and subcutaneous external anal sphincter have yet to be clearly elucidated. This study was designed to measure the motor latencies of these sphincters separately and to investigate the electrophysiologic heterogeneity of the anal sphincter system. In 20 preoperative patients with colon cancer without either neurologic or anorectal diseases, motor evoked potentials were taken separately bilaterally at levels measuring approximately 5, 3.8, 2.6, and 1.5 cm from the perineal skin using a concentric needle electrode after magnetic stimulation on the sacral region. These latencies were considered to be separately measured at the puborectalis, deep, superficial, and subcutaneous external anal sphincter. The motor latencies (median (95 percent confidence interval)) were 4.33 (4.1-4.93; right) and 4.24 (3.97-5.22; left) ms at the 5 cm level; 5.96 (5.45-7.32; right) and 6.44 (5.49-8.20; left) ms at the 3.8 cm level; 9.28 (7.99-11.21; right) and 8.88 (7.68-10.93; left) ms at the 2.6 cm level; and 11.06 (9.69-14.13; right) and 9.18 (8.09-10.31; left) ms at the 1.5 cm level. Significant differences were seen in the latencies between the 5 cm level and the other levels and between the 3.8 cm level and the other levels. The motor latencies in the anal sphincter system significantly varied depending on the distance from the skin. The latency may be shortest in the puborectalis and increasingly longer in the deep, superficial, and subcutaneous EAS, in that order.

Effect of Magnetic Stimulation on the Contractile Activity of the Rectum in Humans

Magnetic stimulation (MS) has been used to activate the neuromuscular tissue by inducing an electric field. Based on the results of a recent study on a canine model (Eur Surg Res 1998;30:268-72), which demonstrated that sacral MS effected a rectal and vesical pressure rise and a drop of rectal neck (anal canal) pressure, thereby achieving evacuation, the test was performed on 28 healthy volunteers (mean age, 36.6 years; 18 men and 10 women). The rectal, rectal neck, and vesical pressures were recorded during sacral MS with a magnetic coil while the rectum was empty and distended by a balloon. Electromyographic activity of the two rectus abdominis muscles was determined to exclude the possible interference of intra-abdominal pressure with the MS recordings. Stimulation parameters were set at 70 per cent intensity, 40-Hz frequency, and 1-to 2-second burst length. Sacral MS effected significant rectal and vesical pressure rise (P < 0.01 and P < 0.01, respectively) and drop of rectal neck pressure (P < 0.01). Intermittent stimulation induced balloon expulsion from the rectum. The two rectus abdominis muscles did not show change in electromyographic activity during MS, indicating that the rectal and vesical pressure rise was not due to increased intra-abdominal pressure. Sacral MS induced rectal evacuation with no adverse effects. The method is simple, easy, safe, and noninvasive and is suggested to be applied for the treatment of the inertic or neuropathic rectum. As the vesical pressure proved to be elevated too, MS might also be used for rectal and vesical evacuation in patients with spinal cord lesions.

Functional magnetic stimulation of the vagus nerve enhances colonic transit time in healthy volunteers

Sacral magnetic stimulation (MS) of the full and empty rectum increases rectal and decreases anal pressures. Rectal evacuation was produced by intermittent MS. MS activates not only the muscles but also the nervous tissue. In the present study I investigated the effect of MS of the vagus nerve on the colonic transit to evaluate the possibility of using this method in the treatment of constipation due to colonic inertia. Forty healthy volunteers were divided into 2 equal groups: study (mean age 46.6 years; 13 men, 7 women) and control (mean age 43.9 years; 13 men, 7 women). MS was produced by a magnetic stimulator and a 2-cm coil placed in the middle of the ventral surface of the neck. MS parameters were set at 70% of maximal intensity, 40 Hz frequency, 10 seconds on, 10 seconds off for 20 minutes and followed by 60 minutes rest. This sequence was performed for 5 cycles. Colonic transit was determined by ingesting 20 radiopaque markers and by radiographing the subject. In the control group, 6 subjects had passed all the markers on the sixth day post-ingestion and all the remaining subjects except two on the seventh day; the last two subjects passed all the markers on the eighth day. In the study group, more than 50% of the subjects had passed all the markers already by the fifth post-ingestion day; the others completed passage of the markers by the sixth day. In the study group 100% of the markers had passed by the sixth post-ingestion day against 30% in the control group. These findings suggest that MS of the vagus nerve enhances colonic transit by augmenting the peristaltic activity of the gut. The procedure might thus be used for the treatment of constipation resulting from delayed colonic transit.

Sacral Magnetic Stimulation in Paradoxical Puborectalis Syndrome

Background/Purpose: Our earlier studies have demonstrated that sacral magnetic stimulation (MS) in the canine model, in healthy volunteers and in constipated subjects brought about a rise in rectal pressure and a decline in rectal neck (anal canal) pressure as well as rectal evacuation. Based on these results, we studied the effect of sacral MS on defecation in patients with paradoxical puborectalis syndrome (PPS). Methods: Eleven subjects (8 women, 3 men; age 36–53 years) with PPS were enrolled in the study. The magnetic coil was placed on the back with its center located between L4 and L5. Stimulation parameters were set at 70% of maximum intensity, 40 Hz frequency and 2 s burst length with 2 s off. During MS, the rectal neck and gastric (intra-abdominal) pressures were measured. The procedure was performed in the empty and the full rectum using the balloon expulsion test in the latter. Results: MS of the empty and balloon-filled rectum brought about a rise in the rectal pressure (p < 0.001), decline in rectal neck pressure (p < 0.001) and no significant change in intragastric pressure (p > 0.05). The balloon was expelled by all patients. Conclusions: Sacral MS succeeded in expelling the water-filled rectal balloon. The method is simple, easy, noninvasive, nonradiologic and can be performed on an outpatient basis in the treatment of PPS.