Neuromuscular electrical stimulation of completely paralyzed abdominal muscles in spinal cord-injured patients: a pilot study

The effect of electromyography triggered electrical stimulation to abdominal muscles on sitting balance, respiratory functions, and abdominal muscle thickness in complete spinal cord injury: a randomized controlled trial

Complete thoracic spinal cord injury (SCI) results in a loss of innervation to the abdominal muscles, which affects trunk stability and performance of activities of daily living from a sitting position. Respiratory function is also affected, leading to frequent pulmonary complications. Given the importance of trunk stability and respiratory function, we investigated the effects of electromyography triggered electrical stimulation (EMG-ES) applied to the abdominal muscles on sitting balance, respiratory functions and abdominal muscle thickness in individuals with complete thoracic SCI. This randomized controlled study included 34 participants with complete thoracic SCI who were randomly allocated to the experimental group ( n  = 17) and the control group ( n  = 17). During the 4-week intervention period, the experimental group received EMG-ES to their abdominal muscles, while the control group received isometric abdominal exercises three times per week. Both groups continued with their routine rehabilitation program (active or passive range of motion exercises, stretching, and balance coordination exercises). The primary outcome measures were the modified functional reach test (mFRT) and trunk control test (TCT). Secondary outcome measures included a pulmonary function test (PFT) and the bilateral abdominal muscle thicknesses using ultrasonography. At the end of the study, the experimental group showed significantly greater improvements in both primary outcomes. The mean difference in pre-post changes between the groups for the mFRT area was 242.8 cm² [95% confidence interval (CI): 181.3-329.8; effect size 0.92; P  < 0.001] and 5.0 points for TCT (95% CI: 3.9-6.0; effect size 0.98, P  < 0.001). The increase in the abdominal muscle thickness was also significantly greater in the experimental group ( P  < 0.001) without significant differences in the PFT ( P  > 0.05). We conclude that adding EMG-ES of abdominal muscles may further improve sitting balance and abdominal muscle thickness in individuals with complete thoracic SCI.

Lack of improvement in anorectal manometry parameters after implementation of a pelvic floor/anal sphincter biofeedback in persons with motor-incomplete spinal cord injury

BACKGROUND

Effect of biofeedback on improving anorectal manometric parameters in incomplete spinal cord injury is unknown. A short-term biofeedback program investigated any effect on anorectal manometric parameters without correlation to bowel symptoms.

METHODS

This prospective uncontrolled interventional study comprised three study subject groups, Group 1: sensory/motor-complete American Spinal Injury Association Impairment Scale (AIS) A SCI (n = 13); Group 2 (biofeedback group): sensory incomplete AIS B SCI (n = 17) (n = 3), and motor-incomplete AIS C SCI (n = 8), and AIS D SCI (n = 6); and Group 3: able-bodied (AB) controls (n = 12). High-resolution anorectal manometry (HR-ARM) was applied to establish baseline characteristics in all subjects for anorectal pressure, volume, length of pressure zones, and duration of sphincter squeeze pressure. SCI participants with motor-incomplete SCI were enrolled in pelvic floor/anal sphincter bowel biofeedback training (2 × 6-week training periods comprised of two training sessions per week for 30-45 min per session). HR-ARM was also performed after each of the 6-week periods of biofeedback training.

RESULTS

Compared to motor-complete or motor-incomplete SCI participants, AB subjects had higher mean intra-rectal pressure, maximal sphincteric pressure, residual anal pressure, recto-anal pressure gradient, and duration of squeeze (p < 0.05 for each of the endpoints). No significant difference was evident at baseline between the motor-complete and motor-incomplete SCI groups. In motor-incomplete SCI subjects, the pelvic floor/anal sphincter biofeedback protocol failed to improve HR-ARM parameters.

CONCLUSION

Biofeedback training program did not improve anal manometric parameters in subjects with motor-incomplete or sensory-incomplete SCI. Biofeedback did not change physiology, and its effects on symptoms are unknown.

INFERENCES

Utility of biofeedback is limited in patients with incomplete spinal cord injury in terms of improving HR-ARM parameters.

Effectiveness of Abdominal Functional Electrical Stimulation for Improving Bowel Function in People With a Spinal Cord Injury: A Study Protocol for a Double-Blinded Randomized Placebo-Controlled Clinical Trial

Background

People with a spinal cord injury (SCI) have a high rate of bowel-related morbidity, even compared with people with other neurological disorders. These complications lower quality of life and place a financial burden on the health system. A noninvasive intervention that improves the bowel function of people with an SCI should reduce morbidity, improve quality of life, and lead to cost savings for health care providers.

Objectives

To investigate the effectiveness of noninvasive abdominal functional electrical stimulation (FES) for improving bowel function in people with a chronic SCI.

Methods

A prospective, double-blinded, 1:1 randomized, placebo-controlled intervention trial will be conducted with 80 adults with chronic SCI (>12 months since injury) above T8 single neurological level. The intervention will be a 45-minute abdominal FES (or placebo) session, 3 days per week, for 6 weeks.

Main Study Parameters/Endpoints

Primary endpoint is whole gut transit time before and after 6 weeks of abdominal FES. Secondary endpoints measured before and after 6 weeks of abdominal FES are (1) colonic transit time; (2) quality of life (EQ-5D-5L); (3) participant-reported bowel function (International SCI Bowel Function Basic Data Set Questionnaire and visual analogue scale); (4) respiratory function (forced vital capacity, forced expiratory volume in 1 second, peak expiratory flow, maximal inspiratory pressure, and maximal expiratory pressure); (5) bladder symptoms (Neurogenic Bladder Symptom Score); (6) daily bowel management diary; and (7) unplanned hospital visits.

Conclusion

Safety data will be collected, and a cost utility analysis using quality of life scores will be performed.

Trial registration

Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12621000386831.

Multifocal Noninvasive Magnetic Stimulation of the Primary Motor Cortex in Type 1 Myotonic Dystrophy -A Proof of Concept Pilot Study

BACKGROUND

Repeated neuromuscular electrical stimulation in type 1 Myotonic Dystrophy (DM1) has previously been shown to cause an increase in strength and a decrease in hyperexcitability of the tibialis anterior muscle.

OBJECTIVE

In this proof-of-principle study our objective was to test the hypothesis that noninvasive repetitive transcranial magnetic stimulation of the primary motor cortex (M1) with a new portable wearable multifocal stimulator causes improvement in muscle function in DM1 patients.

METHODS

We performed repetitive stimulation of M1, localized by magnetic resonance imaging, with a newly developed Transcranial Rotating Permanent Magnet Stimulator (TRPMS). Using a randomized within-patient placebo-controlled double-blind TRPMS protocol, we performed unilateral active stimulation along with contralateral sham stimulation every weekday for two weeks in 6 adults. Methods for evaluation of muscle function involved electromyography (EMG), hand dynamometry and clinical assessment using the Medical Research Council scale.

RESULTS

All participants tolerated the treatment well. While there were no significant changes clinically, EMG showed significant improvement in nerve stimulus-evoked compound muscle action potential amplitude of the first dorsal interosseous muscle and a similar but non-significant trend in the trapezius muscle, after a short exercise test, with active but not sham stimulation.

CONCLUSIONS

We conclude that two-week repeated multifocal cortical stimulation with a new wearable transcranial magnetic stimulator can be safely conducted in DM1 patients to investigate potential improvement of muscle strength and activity. The results obtained, if confirmed and extended by future safety and efficacy trials with larger patient samples, could offer a potential supportive TRPMS treatment in DM1.

The effect of abdominal functional electrical stimulation on bowel function in multiple sclerosis: a cohort study

BACKGROUND

Chronic constipation is prevalent in people with multiple sclerosis, with current treatments usually only partially effective.

OBJECTIVES

This study aims to evaluate the efficacy of abdominal functional electrical stimulation to reduce whole gut and colonic transit times and improve bowel and bladder-related quality of life.

METHODS

A total of 23 people with multiple sclerosis who fulfilled the Rome III criteria for functional constipation applied abdominal functional electrical stimulation for 1 hour per day, 5 days per week, for 6 weeks. Whole gut and colonic transit times and bowel and bladder-related quality of life were measured before and after the intervention period.

RESULTS

Whole gut (mean 81.3 (standard deviation 28.7) hours pre vs. 96.1 (standard deviation 53.6) hours post-intervention, P = 0.160) and colonic transit time (65.1 (31.4) vs. 74.8 (51.1) hours, P = 0.304) were unchanged following 6 weeks of abdominal functional electrical stimulation. There was a significant improvement in bowel (mean 1.78 (SD: 0.64) pre vs. 1.28 (SD: 0.54) post, P = 0.001) and bladder (50.6 (26.49) vs. 64.5 (21.92), p = 0.007) related quality of life after the intervention period.

CONCLUSION

While abdominal functional electrical stimulation did not reduce whole gut and colonic transit times for people with multiple sclerosis, a significant improvement in bowel and bladder-related quality of life was reported.

A therapeutic effect for males with spinal cord injury using abdominal functional electrical stimulation for sexual functioning

INTRODUCTION

Sexual functioning is a high priority for people with a spinal cord injury (SCI) yet this area has received little attention. Two SCI case reports are presented which suggests there may be greater potential for the recovery of sexual functioning than previously recognised.

CASE PRESENTATION

A 74-year-old SCI male (AIS D, C5/C6) and a 36-year-old SCI male (AIS A, T4/T5) were treated for neurogenic bowel using 6 weeks of abdominal FES (ABFES) (40 Hz, 300 µ pulse width (current typically 30-60 MA) simultaneously delivered (8 s contraction with 2 s ramps and 3 s off period) from both channels). The 74-year-old AIS D, C5/C6 participant reported improved strength and duration of erectile function after using ABFES for 3 weeks. The 36-year-old AIS A, T4/T5 participant reported improvements in ejaculatory function and urine flow. Both reported a reduction in time required for bowel management.

DISCUSSION

The findings could be attributed to an improved vascularisation of the abdominal area, an improved body image and self-esteem, direct innervation of nerves involved in parasympathetic pathways or innervation of the T11/T1 area implicated in the alternative psychogenic pathway. Both participants reported they had not used ABFES during sexual activity suggesting a therapeutic effect from the treatment.

Abdominal Functional Electrical Stimulation to Augment Respiratory Function in Spinal Cord Injury

Background: Functional electrical stimulation (FES) is the application of electrical pulses to a nerve to achieve a functional muscle contraction. Surface electrical stimulation of the nerves that innervate the abdominal muscles, termed abdominal FES, can cause the abdominal muscles to contract, even when paralysed after spinal cord injury. As the abdominal muscles are the major expiratory muscles, and commonly partially or completely paralysed in tetraplegia, abdominal FES offers a promising method of improving respiratory function for this patient group. Objective: The aim of the article is to provide readers with a better understanding of how abdominal FES can be used to improve the health of the spinal cord-injured population. Methods: A narrative review of the abdominal FES literature was performed. Results: Abdominal FES can achieve an immediate effective cough in patients with tetraplegia, while the repeated application over 6 weeks of abdominal FES can improve unassisted respiratory function. Ventilator duration and tracheostomy cannulation time can also be reduced with repeated abdominal FES. Conclusion: Abdominal FES is a noninvasive method to achieve functional improvements in cough and respiratory function in acute and chronically injured people with tetraplegia. Potential practical outcomes of this include reduced ventilation duration, assisted tracheostomy decannulation, and a reduction in respiratory complications. All of these outcomes can contribute to reduced morbidity and mortality, improved quality of life, and significant potential cost savings for local health care providers.

Abdominal functional electrical stimulation for bowel management in multiple sclerosis

Aim: Functional constipation is common in multiple sclerosis (MS) and first line treatments are frequently ineffective. The current study explored the use of abdominal functional electrical stimulation (ABFES) for treating constipation in MS. Patients/methods: 20 people with MS and constipation (ROME IV criteria). The patient assessment of constipation-related quality of life questionnaire was administered at baseline and after 6 weeks of ABFES treatment alongside semi-structured interviews. Results: All patient assessment of constipation-related quality of life subscales were significant: satisfaction (p = 0.003), psychosocial discomfort (p = 0.008), physical discomfort (p = 0.001) and worries and concerns (p = 0.003). A long-term therapeutic effect, reduction in laxative use and improved sexual functioning were also reported. Conclusion: ABFES provides a potential alternative treatment intervention for people with MS and constipation.

Stimulation of abdominal and upper thoracic muscles with surface electrodes for respiration and cough: Acute studies in adult canines

OBJECTIVE

To optimize maximal respiratory responses with surface stimulation over abdominal and upper thorax muscles and using a 12-Channel Neuroprosthetic Platform.

METHODS

Following instrumentation, six anesthetized adult canines were hyperventilated sufficiently to produce respiratory apnea. Six abdominal tests optimized electrode arrangements and stimulation parameters using bipolar sets of 4.5 cm square electrodes. Tests in the upper thorax optimized electrode locations, and forelimb moment was limited to slight-to-moderate. During combined muscle stimulation tests, the upper thoracic was followed immediately by abdominal stimulation. Finally, a model of glottal closure for cough was conducted with the goal of increased peak expiratory flow.

RESULTS

Optimized stimulation of abdominal muscles included three sets of bilateral surface electrodes located 4.5 cm dorsal to the lateral line and from the 8^th intercostal space to caudal to the 13^th rib, 80 or 100 mA current, and 50 Hz stimulation frequency. The maximal expired volume was 343 ± 23 ml (n=3). Optimized upper thorax stimulation included a single bilateral set of electrodes located over the 2^nd interspace, 60 to 80 mA, and 50 Hz. The maximal inspired volume was 304 ± 54 ml (n=4). Sequential stimulation of the two muscles increased the volume to 600 ± 152 ml (n=2), and the glottal closure maneuver increased the flow.

CONCLUSIONS

Studies in an adult canine model identified optimal surface stimulation methods for upper thorax and abdominal muscles to induce sufficient volumes for ventilation and cough. Further study with this neuroprosthetic platform is warranted.

Synergistic Activities of Abdominal Muscles Are Required for Efficient Micturition in Anesthetized Female Mice

Purpose

To characterize the electromyographic activity of abdominal striated muscles during micturition in urethane-anesthetized female mice, and to quantitatively evaluate the contribution of abdominal responses to efficient voiding.

Methods

Cystometric and multichannel electromyographic recordings were integrated to enable a comprehensive evaluation during micturition in urethane-anesthetized female mice. Four major abdominal muscle domains were evaluated: the external oblique, internal oblique, and superior and inferior rectus abdominis. To further characterize the functionality of the abdominal muscles, pancuronium bromide (25 μg/mL or 50 μg/mL, abdominal surface) was applied as a blocking agent of neuromuscular junctions.

Results

We observed a robust activation of the abdominal muscles during voiding, with a consistent onset/offset concomitant with the bladder pressure threshold. Pancuronium was effective, in a dose-dependent fashion, for partial and complete blockage of abdominal activity. Electromyographic discharges during voiding were significantly inhibited by applying pancuronium. Decreased cystometric parameters were recorded, including the peak pressure, pressure threshold, intercontractile interval, and voiding duration, suggesting that the voiding efficiency was significantly compromised by abdominal muscle relaxation.

Conclusions

The relevance of the abdominal striated musculature for micturition has remained a topic of debate in human physiology. Although the study was performed on anesthetized mice, these results support the existence of synergistic abdominal electromyographic activity facilitating voiding in anesthetized mice. Further, our study presents a rodent model that can be used for future investigations into micturition-related abdominal activity.

Review of Epidural Spinal Cord Stimulation for Augmenting Cough after Spinal Cord Injury

Spinal cord injury (SCI) remains a debilitating condition for which there is no cure. In addition to loss of somatic sensorimotor functions, SCI is also commonly associated with impairment of autonomic function. Importantly, cough dysfunction due to paralysis of expiratory muscles in combination with respiratory insufficiency can render affected individuals vulnerable to respiratory morbidity. Failure to clear sputum can aggravate both risk for and severity of respiratory infections, accounting for frequent hospitalizations and even mortality. Recently, epidural stimulation of the lower thoracic spinal cord has been investigated as novel means for restoring cough by evoking expiratory muscle contraction to generate large positive airway pressures and expulsive air flow. This review article discusses available preclinical and clinical evidence, current challenges and clinical potential of lower thoracic spinal cord stimulation (SCS) for restoring cough in individuals with SCI.

Breathing-synchronised electrical stimulation of the abdominal muscles in patients with acute tetraplegia: A prospective proof-of-concept study

OBJECTIVE

To examine whether, by enhancing breathing depth and expectoration, early use of breathing-synchronised electrical stimulation of the abdominal muscles (abdominal functional electrical stimulation, AFES) is able to reduce pulmonary complications during the acute phase of tetraplegia.

DESIGN

Prospective proof-of-concept study.

SETTING

Spinal cord unit at a level 1 trauma center.

METHOD

Following cardiovascular stabilisation, in addition to standard treatments, patients with acute traumatic tetraplegia (ASIA Impairment Scale A or B) underwent breathing-synchronised electrical stimulation of the abdominal muscles to aid expiration and expectoration. The treatment was delivered in 30-minute sessions, twice a day for 90 days. The target was for nine of 15 patients to remain free of pneumonia meeting Centers for Disease Control and Prevention (CDC) diagnostic criteria.

RESULTS

Eleven patients were recruited to the study between October 2011 and November 2012. Two patients left the study before completion. None of the patients contracted pneumonia during the study period. No complications from electrical stimulation were observed. AFES led to a statistically significant increase in peak inspiratory and expiratory flows and a non-statistically significant increase in tidal volume and inspiratory and expiratory flow. When surveyed, 6 out of 9 patients (67%) reported that the stimulation procedure led to a significant improvement in breathing and coughing.

CONCLUSION

AFES appears to be able to improve breathing and expectoration and prevent pneumonia in the acute phase of tetraplegia (up to 90 days post-trauma). This result is being validated in a prospective multicentre comparative study.

Uso da eletroestimulação na clínica fonoaudiológica: uma revisão integrativa da literatura

Resumo: Este trabalho tem como objetivo apresentar revisão integrativa de literatura sobre a aplicabilidade e o resultado do uso da eletroestimulação na prática clínica fonoaudiológica. Foram seguidos os preceitos do Cochrane Handbook, que envolveu a formulação da questão a ser investigada, localização e seleção dos estudos e avaliação crítica dos artigos. Foram utilizadas as bases de dados Medical Literature Analysis and Retrieval Sistem on-line (Medline), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), PubMed e Web of Science/ISI. Os descritores utilizados foram: "estimulação elétrica nervosa transcutânea", "estimulação elétrica", "disfagia", "transtornos de deglutição", "disfonia", "distúrbios da voz", "treinamento da voz" e "terapia por estimulação elétrica" em inglês, português e espanhol e suas combinações, no período entre 2003 e 2013. Os estudos analisados demonstraram que a eletroestimulação traz benefícios na reabilitação de pacientes na clínica fonoaudiológica, mas a metodologia utilizada nos estudos foi divergente e a população estudada muito heterogênea o que dificulta sua utilização clínica pelos profissionais da área. A eletroestimulação traz benefícios na reabilitação fonoaudiológica, porém novos estudos devem ser realizados utilizando uma amostra mais homogênea e descrevendo metodologia e técnicas fonoaudiológicas utilizadas nos procedimentos, a fim de comprovar seus resultados e viabilizar seu uso pelos profissionais da área.

Respiratory responses to stimulation of abdominal and upper-thorax intercostal muscles using multiple Permaloc electrodes

Stimulation of abdominal and upper-thoracic muscles was studied with the long-term goal of improved respiratory care for spinal cord injury (SCI) patients. A 12-channel stimulator and multiple surface and implanted Permaloc electrodes were evaluated in five anesthetized canines. Abdominal stimulation with 100 mA using four bilateral sets of surface electrodes placed on the midaxillary line at the 7th through 13th intercostal spaces and with a closed airway at a large lung volume produced an expiratory tracheal pressure of 109 +/- 29 cm H2O (n = 2, mean +/- standard error of the mean). Similar high pressures were induced with implanted electrodes at the same locations. Upper-thoracic stimulation with 40 mA and four sets of implanted electrodes ventral to the axilla induced inspiratory pressures of -12 +/- 2 cm H2O (n = 5). Combined extradiaphragmatic pacing with an open airway produced a tidal volume of 440 +/- 45 mL (n = 4). The robust respiratory volumes and pressures suggest applications in SCI respiratory care.

Bowel management in spinal cord injury patients

Spinal cord injuries are common in the United States, affecting approximately 12,000 people per year. Most of these patients lack normal bowel function. The pattern of dysfunction varies with the spinal level involved. Most patients use a bowel management program, and elements of successful programs are discussed. Surgical treatment, when indicated, could include sacral nerve stimulation, Malone antegrade continence enema, and colostomy.

Changes in pulmonary function measures following a passive abdominal functional electrical stimulation training program

OBJECTIVE

To demonstrate the effect of a passive abdominal functional electrical stimulation (AFES) training program on unassisted respiratory measures in tetraplegia.

DESIGN

Longitudinal feasibility study.

SETTING

National spinal injuries unit in a university teaching hospital.

PARTICIPANTS

Twelve patients with tetraplegic spinal cord injury, who could breathe independently, with reduced vital capacity and no visible abdominal movement.

INTERVENTION

Three weeks of abdominal muscle conditioning using transcutaneous AFES.

MAIN OUTCOME MEASURES

Forced vital capacity (FVC), forced exhaled volume in 1 second (FEV1), peak expiratory flow rate (PEF), and maximum exhaled pressure (MEP).

RESULTS

Mean (SD) FVC increased by 0.36 l (0.23) during training (P = 0.0027). Mean (SD) FEV1 and PEF tended to increase by 0.18 l (0.16) and 0.39 l/seconds (0.35), respectively, but this was not significant. No significant change was found in the outcome measures during a 1-week pre-training control phase and during a 3-week post-training phase.

CONCLUSIONS

The increase in FVC over the training period and the absence of change before or after training suggest that passive abdominal FES training can be used for respiratory rehabilitation in tetraplegia.

Physiotherapy secretion removal techniques in people with spinal cord injury: a systematic review

OBJECTIVE

To address whether secretion removal techniques increase airway clearance in people with chronic spinal cord injury (SCI).

DATA SOURCES AND STUDY SELECTION

MEDLINE/PubMed, CINAHL, EMBASE, and PsycINFO were searched from inception to May 2009 for population keywords (spinal cord injury, paraplegia, tetraplegia, quadriplegia) paired with secretion removal-related interventions and outcomes. Inclusion criteria for articles were a research study, irrespective of design, that examined secretion removal in people with chronic SCI published in English.

REVIEW METHODS

Two reviewers determined whether articles met the inclusion criteria, abstracted information, and performed a quality assessment using PEDro or Downs and Black criteria. Studies were then given a level of evidence based on a modified Sackett scale.

RESULTS

Of 2416 abstracts and titles retrieved, 24 met the inclusion criteria. Subjects were young (mean, 31 years) and 84% were male. Most evidence was level 4 or 5 and only 2 studies were randomized controlled trials. Three reports described outcomes for secretion removal techniques in addition to cough, whereas most articles examined the immediate effects of various components of cough. Studies examining insufflation combined with manual assisted cough provided the most consistent, high-level evidence. Compelling recent evidence supports the use of respiratory muscle training or electrical stimulation of the expiratory muscles to facilitate airway clearance in people with SCI.

CONCLUSION

Evidence supporting the use of secretion removal techniques in SCI, while positive, is limited and mostly of low level. Treatments that increase respiratory muscle force show promise as effective airway clearance techniques.

Neurogenic bowel management after spinal cord injury: a systematic review of the evidence

STUDY DESIGN

Randomized-controlled trials (RCTs), prospective cohort, case-control, pre-post studies, and case reports that assessed pharmacological and non-pharmacological intervention for the management of the neurogenic bowel after spinal cord injury (SCI) were included.

OBJECTIVE

To systematically review the evidence for the management of neurogenic bowel in individuals with SCI.

SETTING

Literature searches were conducted for relevant articles, as well as practice guidelines, using numerous electronic databases. Manual searches of retrieved articles from 1950 to July 2009 were also conducted to identify literature.

METHODS

Two independent reviewers evaluated each study's quality, using Physiotherapy Evidence Database scale for RCTs and Downs and Black scale for all other studies. The results were tabulated and levels of evidence assigned.

RESULTS

A total of 2956 studies were found as a result of the literature search. On review of the titles and abstracts, 57 studies met the inclusion criteria. Multifaceted programs are the first approach to neurogenic bowel and are supported by lower levels of evidence. Of the non-pharmacological (conservative and non-surgical) interventions, transanal irrigation is a promising treatment to reduce constipation and fecal incontinence. When conservative management is not effective, pharmacological interventions (for example prokinetic agents) are supported by strong evidence for the treatment of chronic constipation. When conservative and pharmacological treatments are not effective, surgical interventions may be considered and are supported by lower levels of evidence in reducing complications.

CONCLUSIONS

Often, more than one procedure is necessary to develop an effective bowel routine. Evidence is low for non-pharmacological approaches and high for pharmacological interventions.

Stimulating multiple respiratory muscles with intramuscular Permaloc electrodes

OBJECTIVE

To test the feasibility of implanting intramuscular electrodes (Permaloc, Synapse Biomedical Inc, Oberlin OH) with self-securing polypropylene anchors to stimulate upper-intercostal and abdominal muscles plus the diaphragm.

METHODS/RESULTS

In 6 anesthetized dogs, 12 Permaloc electrodes were implanted in the 3 respiratory muscles (4 in each muscle group). Tidal volume with diaphragmatic stimulation was 310 +/- 38 mL (mean +/- SE); with upper intercostal stimulation, it was 68 +/- 18 mL; and with combined diaphragm intercostal stimulation, it was 438 +/- 78 mL. By study design, stimulation in the upper intercostal muscles was limited to not more than slight/moderate contraction of the serratus and latissimus muscles overlying the ribs. Abdominal muscle stimulation produced exhaled volumes of 38 +/- 20 mL (this stimulation was limited by the maximal output of the stimulator of 25 milliamperes). Combined diaphragm intercostal stimulation followed by abdominal muscle stimulation increased exhaled volumes from 312 +/- 31 mL to 486 +/- 58 mL (P = 0.024).

CONCLUSIONS

Permaloc electrodes can be successfully implanted in upper intercostal and abdominal muscles in addition to the diaphragm. Combined diaphragm intercostal stimulation followed by abdominal muscle stimulation increased the exhaled volumes recorded with diaphragmatic stimulation alone.