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

Effect of magnetic therapy in bladder dysfunction and quality of life in paraplegic patients

BACKGROUND

Urinary dysfunction is linked to spinal cord injury (SCI). The quality of life (QoL) declines in both neurogenic bladder impairment and non-disordered patients.

OBJECTIVE

To ascertain the effectiveness of pulsed magnetic therapy on urinary impairment and QoL in individuals with traumatic incomplete SCI.

METHODS

This study included forty male paraplegic subjects with neurogenic detrusor overactivity (NDO) for more than one year following incomplete SCI between T6-T12. Their ages ranged from 20 to 35 and they engaged in therapy for three months. The subjects were divided into two groups of equal size. Individuals in Group I were managed via pulsed magnetic therapy once per week plus pelvic floor training three times a week. Individuals in Group II were managed with only three times a week for pelvic floor training. All patients were examined for bladder cystometric investigations, pelvic-floor electromyography (EMG), and SF-Qualiveen questionnaire.

RESULTS

There was a noteworthy increment in individuals in Group I in volume of bladder at first desire to void and maximum cystometric capacity, detrusor pressure at Qmax, and maximum flow rate. There was a momentous increment in Group I in measures of evaluation of EMG biofeedback. There was a notable rise in Group I in SF-Qualiveen questionnaire.

CONCLUSION

Magnetic stimulation should be favored as beneficial adjunct to traditional therapy in the management of bladder impairment and enhancing QoL in individuals with SCI.

Bioelectronic medicine for the autonomic nervous system: clinical applications and perspectives

Bioelectronic medicine (BM) is an emerging new approach for developing novel neuromodulation therapies for pathologies that have been previously treated with pharmacological approaches. In this review, we will focus on the neuromodulation of autonomic nervous system (ANS) activity with implantable devices, a field of BM that has already demonstrated the ability to treat a variety of conditions, from inflammation to metabolic and cognitive disorders. Recent discoveries about immune responses to ANS stimulation are the laying foundation for a new field holding great potential for medical advancement and therapies and involving an increasing number of research groups around the world, with funding from international public agencies and private investors. Here, we summarize the current achievements and future perspectives for clinical applications of neural decoding and stimulation of the ANS. First, we present the main clinical results achieved so far by different BM approaches and discuss the challenges encountered in fully exploiting the potential of neuromodulatory strategies. Then, we present current preclinical studies aimed at overcoming the present limitations by looking for optimal anatomical targets, developing novel neural interface technology, and conceiving more efficient signal processing strategies. Finally, we explore the prospects for translating these advancements into clinical practice.

Translumbosacral Neuromodulation Therapy Is a Promising Option for Fecal Incontinence

ABSTRACT

Fecal incontinence is a common symptom that can significantly impair quality of life. The treatment options range from conservative measures (e.g., Kegel exercises, pelvic floor biofeedback therapy, fiber supplementation, or medications) to noninvasive nerve stimulation (e.g., posterior tibial nerve stimulation and transcutaneous tibial nerve stimulation), implanted neurostimulation (i.e., sacral nerve stimulation), perianal injection of dextranomer, and anal sphincteroplasty. In this issue of the journal, a promising, uncontrolled study suggests that noninvasive, repetitive magnetic stimulation of the lumbosacral nerves significantly improved symptoms, increased anal squeeze pressure, and increased rectal compliance in patients with fecal continence. Sham-controlled studies are necessary to confirm these findings.

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

BACKGROUND

Sacral nerve stimulation (SNS) is an alternative surgical treatment of refractory urge incontinence and/or fecal incontinence. Despite its clinical efficacy, the mechanisms of action of SNS remain poorly understood. The aim of this experimental study was to evaluate the effect of SNS on visceral mechanosensitivity in rats.

METHODS

Anesthetized Sprague-Dawley rats were treated with SNS or sham stimulation. SNS was performed by implanting an electrode close to the sacral nerve root S1. Rats were administered either a non-selective opioid receptor antagonist (naloxone) or a nitric oxide synthase inhibitor (L-NAME). Colonic mechanosensitivity was evaluated using the variation of arterial blood pressure as a spino-bulbar reflex in response to graded isobaric colorectal distension (CRD). C-fos immunoreactive neurons were quantified in spinal and supraspinal sites. μ-opioid receptor (MOR) internalization was counted in the sacral spinal cord with sham or effective SNS in response to CRD.

KEY RESULTS

SNS reduced visceral mechanosensitivity in response to CRD. This effect was reversed by intrathecal and intraveinous naloxone administration. In both models, CRD induced increased c-fos immunoreactivity in the dorsal horn neurons of the sacral spinal cord and supraspinal areas. This increase was prevented by SNS. MOR internalization was significantly higher in stimulated group.

CONCLUSIONS & INFERENCES

SNS impacts on visceral mechanosensitivity by decreasing the spino-bulbar reflex in response to CRD. Spinal opioid receptors are likely involved in this effect.

Neurostimulation for neurogenic bowel dysfunction

Background. Loss of normal bowel function caused by nerve injury, neurological disease or congenital defects of the nervous system is termed neurogenic bowel dysfunction (NBD). It usually includes combinations of fecal incontinence, constipation, abdominal pain and bloating. When standard treatment of NBD fails surgical procedures are often needed. Neurostimulation has also been investigated, but no consensus exists about efficacy or clinical use. Methods. A systematic literature search of NBD treated by sacral anterior root stimulation (SARS), sacral nerve stimulation (SNS), peripheral nerve stimulation, magnetic stimulation, and nerve re-routing was made in Pubmed, Embase, Scopus, and the Cochrane Library. Results. SARS improves bowel function in some patients with complete spinal cord injury (SCI). Nerve re-routing is claimed to facilitate defecation through mechanical stimulation of dermatomes in patients with complete or incomplete SCI or myelomeningocele. SNS can reduce NBD in selected patients with a variety of incomplete neurological lesions. Peripheral stimulation using electrical stimulation or magnetic stimulation may represent non-invasive alternatives. Conclusion. Numerous methods of neurostimulation to treat NBD have been investigated in pilot studies or retrospective studies. Therefore, larger controlled trials with well-defined inclusion criteria and endpoints are recommended before widespread clinical use of neurostimulation against NBD.

Botulinum A toxin as a treatment for overactive rectum with associated faecal incontinence

AIM

Rectal hypercontractility can lead to faecal incontinence (FI). Botulinum toxin (BT) has been used successfully for the treatment of bladder overactivity. This study aimed to evaluate the therapeutic value of intrarectal injections of BT in inhibiting colorectal contractions and relieving FI in patients suffering from FI as a result of overactive rectal contractions.

METHOD

A prospective open study was carried out in Rouen University Hospital. Six patients (four men and two women) with severe FI related to overactive rectal contractions underwent intrarectal submucosal injections of BT placed in three rows of 10, 1-ml injections (50 U/1 ml; Dysport(®)) starting 1 cm above the dentate line and repeated twice, at intervals of 5 cm proximally. The end-points included improvement in the FI score, in faecal incontinence quality of life (FIQL) and of manometric abnormality.

RESULTS

All patients reported improvement in the FI score [18.2±1.1 at baseline vs 9.0±1.7 at 3 months (P=0.04)] and in FIQL. Rectal contractile activity was reduced. The frequency of contractions remained unaffected (28.1±6.6/h; P=0.46 vs baseline). High-amplitude contractions of >50 cmH(2)O were significantly decreased in all patients (16.6±3.9 vs 6.6±4.1/h; P=0.03).

CONCLUSION

Patients with an 'overactive rectum' are a heterogeneous group, with varying causes of dysfunction. The dose of BT used was arbitrarily selected. Nevertheless, the study introduces a further therapeutic option in the treatment of FI caused by rectal overactivity.

How sacral nerve stimulation works in patients with faecal incontinence

AIM

Sacral nerve stimulation (SNS) reduces incontinence episodes and improves the quality of life of patients treated for faecal incontinence. However, the exact mechanism of action of this technique remains unclear. The present article reviews the pertinent neuroanatomy and neurophysiology related to SNS and provides explanations for potential mechanisms of action.

METHOD

A systematic review of the literature was performed for studies of the potential mechanisms of action of SNS, using MEDLINE, PubMed, Embase and the Cochrane Library. Articles dealing with the technique, adverse events and economic evaluations of SNS, as well as literature reviews, were excluded, except for reviews dealing with the mechanisms of action of SNS. The following inclusion criteria were used to select articles: (i) articles in English, (ii) randomized, double-blinded, sham-controlled studies, and (iii) cohort studies. Case-control studies or retrospective studies were cited only when randomized or cohort studies could not be found.

RESULTS

We propose three hypotheses to explain the mechanism of action of SNS: (i) a somato-visceral reflex, (ii) a modulation of the perception of afferent information, and (iii) an increase in external anal sphincter activity.

CONCLUSION

The mechanism of action of SNS in patients with faecal incontinence almost certainly depends on the modulation of spinal and/or supraspinal afferent inputs. Further research on humans and animals will be required to gain a better understanding of the mechanisms of action of SNS.

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

BACKGROUND AND PURPOSE

The effects of neuromodulation with sacral magnetic stimulation (SMS) were examined in postoperative patients with bowel or bladder dysfunction.

PATIENTS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

These results suggest that SMS might be a useful modality to improve postoperative bowel or bladder dysfunction.

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

AIM

Sacral nerve stimulation (SNS) has a place in the treatment algorithm for faecal incontinence (FI). However, after implantation, 15-30% of patients with FI fail to respond for unknown reasons. We investigated the effect of SNS on continence and quality of life (QOL) and tried to identify specific predictive factors of the success of permanent SNS in the treatment of FI.

METHOD

Two hundred consecutive patients (six men; median age = 60; range 16-81) underwent permanent implantation for FI. The severity of FI was evaluated by the Cleveland Clinic Score. Quality of life was evaluated by the French version of the American Society of Colon and Rectal Surgeons (ASCRS) quality of life questionnaire (FIQL). All patients underwent a preoperative evaluation. After permanent implantation, severity and QOL scores were reevaluated after six and 12 months and then once a year.

RESULTS

The severity scores were significantly reduced during SNS (P = 0.001). QOL improved in all domains. At the 6-month follow-up, the clinical outcome of the permanent implant was not affected by age, gender, duration of symptoms, QOL, main causes of FI, anorectal manometry or endoanal ultrasound results. Only loose stool consistency (P = 0.01), persistent FI even though diarrhoea was controlled by medical treatment (P = 0.004), and low stimulation intensity (P = 0.02) were associated with improved short-term outcomes. Multivariate analysis confirmed that loose stool consistency and low stimulation intensity were related to a favourable outcome.

CONCLUSION

Stool consistency and low stimulation intensity have been identified as predictive factors for the short-term outcome of SNS.

Technical advances in monitoring human motility patterns

Abnormal motor patterns are implicated in many motility disorders. However, for many regions of the gut, our knowledge of normal and abnormal motility behaviors and mechanisms remains incomplete. There have been many recent advances in the development of techniques to increase our knowledge of gastrointestinal motility, some readily available while others remain confined to research centers. This review highlights a range of these recent developments and examines their potential to help diagnose and guide treatment for motility disorders.

What we have learned about colonic motility: normal and disturbed

PURPOSE OF REVIEW

Disorders of colonic motor and sensory function are common among children and adults and pose significant diagnostic and therapeutic challenges; the purpose of this review, therefore, was to critically assess the recent literature on this topic.

RECENT FINDINGS

Considerable progress has been made at the ultrastructural, molecular and electrophysiological level in understanding the normal functions of the muscles, nerves and interstitial cells that generate and control colonic motility. Furthermore, abnormalities in these cell types and in the interstitial cells of Cajal, in particular, have been identified in a number of disease states. Testing of colonic motor and sensory function in clinical practice continues to be a challenge due, in part, not only to the technical issues presented by accessing the organ but also to the intrinsic variability of its physiology. These have not been auspicious times for advances in the therapy of disturbed colonic motility; new agents or new applications for 'old' agents continue to be explored as are more innovative approaches such as those based on neural stimulation and cell therapy.

SUMMARY

Considerable progress has been made in understanding the basic pathophysiology of colonic dysmotility; clinical diagnostics and therapeutics continue to lag behind.