Functional magnetic stimulation of the colon in persons with spinal cord injury

Neurogenic Bowel Dysfunction in Patients with Spinal Cord Injury and Multiple Sclerosis-An Updated and Simplified Treatment Algorithm

Neurogenic bowel dysfunction (NBD) is a common condition in individuals with spinal cord injury (SCI) or multiple sclerosis (MS). It usually entails constipation, difficult evacuation of the rectum, and fecal incontinence (FI); often in combination. It is highly burdensome for affected patients and is correlated with poor quality of life. The current treatment algorithm, or treatment pyramid, does not completely correspond to actual clinical practice, and the known and classical pyramid contains both treatments still in their experimental stage as well as several treatments which are not available at all treatment centers. Thus, an updated treatment algorithm is called upon, and the authors of this paper therefore propose a simplified version of the treatment pyramid, aiming to guide clinicians in treating NBD.

The Effect of Non-invasive Spinal Cord Stimulation on Anorectal Function in Individuals With Spinal Cord Injury: A Case Series

Spinal cord injury (SCI) is a devastating condition that impacts multiple organ systems. Neurogenic bowel dysfunction (NBD) frequently occurs after a SCI leading to reduced sensation of bowel fullness and bowel movement often leading to constipation or fecal incontinence. Spinal Neuromodulation has been proven to be a successful modality to improve sensorimotor and autonomic function in patients with spinal cord injuries. The pilot data presented here represents the first demonstration of using spinal neuromodulation to activate the anorectal regions of patients with spinal cord injuries and the acute and chronic effects of stimulation. We observed that spinal stimulation induces contractions as well as changes in sensation and pressure profiles along the length of the anorectal region. In addition, we present a case report of a patient with a SCI and the beneficial effect of spinal neuromodulation on the patient’s bowel program.

Transabdominal Functional Magnetic Stimulation for the Treatment of Constipation in Brain-Injured Patients: A Randomized Controlled Trial

Objective

To investigate the effects of the transabdominal functional magnetic stimulation (A-FMS) for constipation in stroke or brain-injured patients.

Methods

Twenty-four brain-injured patients (11 males and 13 females; median age, 65 years; 22 cases of stroke and 2 cases of traumatic brain injury) with constipation, who were admitted to the rehabilitation department, were enrolled and randomly divided into magnetic stimulation (MS) group and sham stimulation (Sham) group. Several parameters related with constipation such as total and segmental colon transit time (CTT), defecation frequency, and Bristol Stool Scale (BSS) before and after 2 weeks of A-FMS (5 times per week, total 10 times of A-FMS) were evaluated. The Korean version of the Modified Barthel Index (K-MBI) was also evaluated.

Results

A significant decrease in segmental CTT in the left colon (-8.2±3.9 vs. 4.1±2.5 hours; p<0.05 by paired sample t-test) and a significant increase in the frequency of defecation (1.5±0.2 vs 0.7±0.3; p<0.05 by paired sample t-test) were observed in the MS group compared with the Sham group. Stool hardness became significantly softer in the MS group compared with the Sham group (2.3–3.5 in the MS and 2.6–3.1 in the Sham; p<0.05 by chi-square test) as evaluated by BSS. No difference in the K-MBI was observed between the two groups.

Conclusion

The present study suggests that A-FMS can be an additional therapeutic tool for managing constipation in brain-injured patients with abnormal bowel movement, defecation frequency, and stool hardness.

Bowel Dysfunction in Spinal Cord Injury

PURPOSE OF REVIEW

To evaluate and report current evidence regarding the management of bowel dysfunction in spinal cord injury. There is a paucity of high-quality large studies on which to base management advice.

RECENT FINDINGS

Recent research has focused on defining the nature of symptomatology of bowel dysfunction in SCI and describing the effects on quality of life and social interactions. Technical aspects of colonoscopy have received attention, and aspects of understanding the pathophysiology in relation to both neural and non-neural dysfunction have been studied. There has been refinement and expansion of the pharmacological and non-pharmacological treatment options for bowel dysfunction in SCI. Management of bowel dysfunction in SCI requires a comprehensive and individualized approach, encompassing lifestyle, toileting routine, stimulation, diet, medications, and surgery. Further high-quality research is required to inform best practice.

Influence of repetitive peripheral magnetic stimulation on neural plasticity in the motor cortex related to swallowing

The aim of this study was to evaluate the effect of repetitive peripheral magnetic stimulation at two different frequencies (20 and 30 Hz) on cortical excitability in motor areas related to swallowing in healthy individuals. The study participants were 10 healthy normal volunteers (two women and eight men, age range 25-36 years). Repetitive peripheral magnetic stimulation was applied to the submandibular muscle using a parabolic coil at the site where contraction of the suprahyoid muscles was elicited. Stimulation was continued for 10 min (total 1200 pulses) at 20 Hz on 1 day and at 30 Hz on another day, with the stimulation strength set at 90% of the intensity that elicited pain. The motor-evoked potential amplitude of suprahyoid muscles was assessed before, immediately after, and 30 min after stimulation. Stimulations at both 20 and 30 Hz significantly increased motor-evoked potential amplitude (P<0.05), with the increase maintained until 30 min after stimulation. The motor-evoked potential amplitude immediately after stimulation was not significantly different between the 20 and 30 Hz frequencies. The results indicated that repetitive magnetic stimulation increased motor-evoked potential amplitude of swallowing muscles, suggesting facilitation of the motor cortex related to swallowing in healthy individuals.

Abnormal feeding behaviour in spinalised rats is mediated by hypothalamus: Restorative effect of exposure to extremely low frequency magnetic field

STUDY DESIGN

Experimental study.

OBJECTIVES

To investigate the role of hypothalamus in abnormal feeding behaviour after spinal cord injury (SCI) and the effect of exposure to extremely low frequency magnetic field (ELF-MF) on it.

SETTING

India.

METHODS

Male Wistar rats (n=44) were divided into Sham (laminectomy), SCI (complete transection of T13 spinal cord), SCI+MF (ELF-MF exposure to SCI rats), VMHL (lesion of ventromedial hypothalamus; VMH), SCI+VMHL (VMHL after SCI) and SCI+VMHL+MF (ELF-MF exposure to SCI+VMHL rats) groups. Food intake (FI), water intake (WI), calorie intake (CI), body weight (BWT), taste preference and sucrose-induced biphasic (SIB) response to noxious stimulus were studied pre and post surgery. Neuronal activity at VMH was assessed by c-Fos immunohistochemistry. The extent of neuronal degeneration and regeneration in spinal cord was assessed microscopically.

RESULTS

Data revealed post-SCI decrease in FI, WI, CI and BWT, preference for sodium chloride and citric acid, prolonged analgesic phase of SIB and increased c-Fos immunoreactivity in VMH of SCI rats vs Sham rats. VMH lesion increased FI, WI, CI, BW, preference for sweet tastants and abolished SIB, whereas in SCI+VMHL rats it abolished the effects of SCI on these parameters indicating probable involvement of VMH in SCI-induced alteration in feeding behaviour. Exposure to MF improved the study parameters in SCI rats and reduced the c-Fos immunoreactivity in VMH besides reduction in lesion volume, greater myelination and neuronal regeneration at SCI site.

CONCLUSION

SCI influences VMH, leading to alteration in feeding behaviour, which is improved by exposure to ELF-MF.

Repetitive Peripheral Magnetic Stimulation With Intensive Swallowing Rehabilitation for Poststroke Dysphagia: An Open-Label Case Series

OBJECTIVE

The purpose of this pilot study was to determine the safety and feasibility of a six-day protocol of in-hospital repetitive peripheral magnetic stimulation combined with intensive swallowing rehabilitation (rPMS-ISR) for poststroke dysphagia.

METHODS

The subjects were eight patients with dysphagia caused by bilateral cerebral infarction (age: 62-70; time from onset of stroke: 27-39 months). rPMS was applied to the suprahyoid muscles, at strength set at 90% of the minimal intensity that elicited pain with a parabolic coil. One train of stimuli comprised 20 Hz for 3 sec followed by 27-sec rest. A single session included delivery of repetitive 20 trains of stimuli over 10 min, followed by 20 min of swallowing rehabilitation. Each patient received this combination treatment twice daily, morning and afternoon, over six consecutive days. Swallowing function was evaluated before and after intervention.

RESULTS

rPMS-ISR induced significant improvement in swallowing ability, laryngeal elevation delay time, penetration aspiration scale, and swallowing quality of life (p < 0.01), but had no significant effect on the functional oral intake scale.

CONCLUSION

The six-day in-hospital RPMS-ISR protocol seems safe and feasible for poststroke patients with dysphagia. The combination protocol improved swallowing function. Further larger studies are needed to confirm its efficacy.

Iron oxide nanoparticles and magnetic field exposure promote functional recovery by attenuating free radical-induced damage in rats with spinal cord transection

BACKGROUND

Iron oxide nanoparticles (IONPs) can attenuate oxidative stress in a neutral pH environment in vitro. In combination with an external electromagnetic field, they can also facilitate axon regeneration. The present study demonstrates the in vivo potential of IONPs to recover functional deficits in rats with complete spinal cord injury.

METHODS

The spinal cord was completely transected at the T11 vertebra in male albino Wistar rats. Iron oxide nanoparticle solution (25 μg/mL) embedded in 3% agarose gel was implanted at the site of transection, which was subsequently exposed to an electromagnetic field (50 Hz, 17.96 μT for two hours daily for five weeks).

RESULTS

Locomotor and sensorimotor assessment as well as histological analysis demonstrated significant functional recovery and a reduction in lesion volume in rats with IONP implantation and exposure to an electromagnetic field. No collagenous scar was observed and IONPs were localized intracellularly in the immediate vicinity of the lesion. Further, in vitro experiments to explore the cytotoxic effects of IONPs showed no effect on cell survival. However, a significant decrease in H2O2-mediated oxidative stress was evident in the medium containing IONPs, indicating their free radical scavenging properties.

CONCLUSION

These novel findings indicate a therapeutic role for IONPs in spinal cord injury and other neurodegenerative disorders mediated by reactive oxygen species.

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.

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.

Optimal electrode placement for noninvasive electrical stimulation of human abdominal muscles

Abdominal muscles are the most important expiratory muscles for coughing. Spinal cord-injured patients have respiratory complications because of abdominal muscle weakness and paralysis and impaired ability to cough. We aimed to determine the optimal positioning of stimulating electrodes on the trunk for the noninvasive electrical activation of the abdominal muscles. In six healthy subjects, we compared twitch pressures produced by a single electrical pulse through surface electrodes placed either posterolaterally or anteriorly on the trunk with twitch pressures produced by magnetic stimulation of nerve roots at the T10level. A gastroesophageal catheter measured gastric pressure (Pga) and esophageal pressure (Pes). Twitches were recorded at increasing stimulus intensities at functional residual capacity (FRC) in the seated posture. The maximal intensity used was also delivered at total lung capacity (TLC). At FRC, twitch pressures were greatest with electrical stimulation posterolaterally and magnetic stimulation at T10and smallest at the anterior site (Pga, 30 ± 3 and 33 ± 6 cmH2O vs. 12 ± 3 cmH2O; Pes 8 ± 2 and 11 ± 3 cmH2O vs. 5 ± 1 cmH2O; means ± SE). At TLC, twitch pressures were larger. The values for posterolateral electrical stimulation were comparable to those evoked by thoracic magnetic stimulation. The posterolateral stimulation site is the optimal site for generating gastric and esophageal twitch pressures with electrical stimulation.

Effects of therapeutic magnetic stimulation on acute muscle atrophy in rats after hindlimb suspension

In most subjects with spinal cord injury, the spinal neurons below the level of injury are spared. Therefore, it is conceivable that the skeletal muscles innervated by these spinal nerves can be activated by applying therapeutic magnetic stimulation along the dorsal spine. The purpose of this study was to evaluate the ability of magnetic stimulation to prevent acute muscle atrophy in rats after hindlimb suspension. Forty adult male Wistar rats were randomly assigned to stimulated and non-stimulated (control) groups. Their hindlimbs were unweighted using a suspension method, causing muscle atrophy. In the stimulation group, magnetic stimulation (20 Hz, 60 min per day) was applied to the sciatic nerve for 10 days. After the stimulation period, the tibialis anterior (TA) and extensor digitorum longus (EDL) were surgically removed and histologically measured. The lesser diameters of type 1, 2A, and 2B muscle fibers were significantly greater in the stimulated group than in the non-stimulated group for both the TA and EDL (p < 0.05). The mean difference in lesser fiber diameter was 20% (range, 14%-27%). These results suggest that therapeutic magnetic stimulation is an effective method of preventing muscle atrophy.

Optimal arrangement of magnetic coils for functional magnetic stimulation of the inspiratory muscles in dogs

In an attempt to maximize inspiratory pressure and volume, the optimal position of a single or of dual magnetic coils during functional magnetic stimulation (FMS) of the inspiratory muscles was evaluated in twenty-three dogs. Unilateral phrenic magnetic stimulation (UPMS) or bilateral phrenic magnetic stimulation (BPMS), posterior cervical magnetic stimulation (PCMS), anterior cervical magnetic stimulation (ACMS) as well as a combination of PCMS and ACMS were performed. Trans-diaphragmatic pressure (Pdi), flow, and lung volume changes with an open airway were measured. Transdiaphragmatic pressure was also measured with an occluded airway. Changes in inspiratory parameters during FMS were compared with 1) electrical stimulation of surgically exposed bilateral phrenic nerves (BPES) and 2) ventral root electrical stimulation at C5-C7 (VRES C5-C7). Relative to the Pdi generated by BPES of 36.3 +/- 4.5 cm H2O (Mean +/- SEM), occluded Pdi(s) produced by UPMS, BPMS, PCMS, ACMS, and a combined PCMS + ACMS were 51.7%, 61.5%, 22.4%, 100.3%, and 104.5% of the maximal Pdi, respectively. Pdi(s) produced by UPMS, BPMS, PCMS, ACMS, and combined ACMS + PCMS were 38.0%, 45.2%, 16.5%, 73.8%, and 76.8%, respectively, of the Pdi induced by VRES (C5-C7) (48.0 +/- 3.9 cm H2O). The maximal Pdi(s) generated during ACMS and combined PCMS + ACMS were higher than the maximal Pdi(s) generated during UPMS, BPMS, or PCMS (p < 0.05). ACMS alone induced 129.8% of the inspiratory flow (73.0 +/- 9.4 L/ min) and 77.5% of the volume (626 +/- 556 ml) induced by BPES. ACMS and combined PCMS + ACMS produce a greater inspiratory pressure than UPMS, BPMS or PCMS. ACMS can be used to generate sufficient inspiratory pressure, flow, and volume for activation of the inspiratory muscles.

Modulation of cardiovascular excitatory responses in rats by transcutaneous magnetic stimulation: role of the spinal cord

This study investigated the efficacy of magnetic stimulation on the reflex cardiovascular responses induced by gastric distension in anesthetized rats and compared these responses to those influenced by electroacupuncture (EA). Unilateral magnetic stimulation (30% intensity, 2 Hz) at the Jianshi-Neiguan acupoints (pericardial meridian, P 5-6) overlying the median nerve on the forelimb for 24 min significantly decreased the reflex pressor response by 32%. This effect was noticeable by 20 min of magnetic stimulation and continued for 24 min. Median nerve denervation abolished the inhibitory effect of magnetic stimulation, indicating the importance of somatic afferent input. Unilateral EA (0.3-0.5 mA, 2 Hz) at P 5-6 using similar durations of stimulation similarly inhibited the response (35%). The inhibitory effects of EA occurred earlier and were marginally longer (20 min) than magnetic stimulation. Magnetic stimulation at Guangming-Xuanzhong acupoints (gallbladder meridian, GB 37-39) overlying the superficial peroneal nerve on the hindlimb did not attenuate the reflex. Intravenous naloxone immediately after termination of magnetic stimulation reversed inhibition of the cardiovascular reflex, suggesting involvement of the opioid system. Also, intrathecal injection of delta- and kappa-opioid receptors antagonists, ICI174,864 (n=7) and nor-binaltorphimine (n=6) immediately after termination of magnetic stimulation reversed inhibition of the cardiovascular reflex. In contrast, the mu-opioid antagonist CTOP (n=7) failed to alter the cardiovascular reflex. The endogenous neurotransmitters for delta- and kappa-opioid receptors, enkephalins and dynorphin but not beta-endorphin, therefore appear to play significant roles in the spinal cord in mediating magnetic stimulation-induced modulation of cardiovascular reflex responses.

The effect of magnetic stimulation on unloaded soleus muscle of rat: changes in myosin heavy chain mRNA isoforms

This study assessed the potential application and the effectiveness of functional magnetic stimulation (FMS) for preventing skeletal muscle atrophy in adult rats. FMS using magnetic stimulator was performed to rat soleus muscle by placing a round magnetic coil on the back of 3rd-5th lumbar vertebral level at 20 Hz frequency for 60 min/day up to 10 days. A reverse transcriptase-polymerase chain reaction was applied to evaluate relative amounts of mRNAs specific to four myosin heavy chain (MHC) isoforms [MHCIbeta, MHCIIa, MHCIIb, and MHCIId(x)] in rat soleus muscle during contractile activity by magnetic stimulation. Ten-day unloading by hindlimb suspension induced a drastic decrease of MHCIbeta and MHCIIa mRNA expressions, while MHCIIb and MHCIId(x) mRNA was not decreased. The magnetic stimulation resuscitated the down-regulation of the mRNA levels of MHCIbeta and MHCIIa. These results suggest that magnetic stimulation on acute atrophied muscles is useful for preventing the muscle atrophy.

Functional magnetic stimulation of the spinal cord?a urodynamic study in healthy humans

AIMS

To study the effects of functional magnetic stimulation of the spinal cord in healthy subjects on somatic and autonomic pathways innervating the anal and the external urethral sphincter, bladder, bladder neck, and rectum.

METHODS

Eight healthy male volunteers gave their written informed consent and underwent functional magnetic stimulation of the thoracolumbar and sacral spinal cord. A two-channel microtip pressure transducer catheter was placed rectally measuring the abdominal and anal sphincter pressure. A three-channel microtip pressure transducer catheter was inserted into the urethra measuring the bladder, the bladder neck, and the external urethral sphincter pressure. A comprehensive protocol of single and repetitive magnetic stimulations was performed. Frequency, location, and duration of stimulation were varied while the intensity of stimulation was adapted to the maximum the subjects could tolerate. In four subjects, the degree of bladder filling was changed and the protocol was repeated when the subjects reported a full bladder and desire to void.

RESULTS

Continuous magnetic stimulation of the thoracolumbar spinal cord and the sacral roots applied with different frequencies (5, 15, 30, 60, 100 Hz) and different duration of stimulation (10, 30, 120 sec) evoked sphincter contraction of both anal and urethral sphincters. The stimulation could not evoke contractions of the bladder, the bladder neck, or the rectum. Also with filled bladder and present desire to void, the magnetic stimulation could not activate autonomic pathways innervating these structures.

CONCLUSIONS

Considering our results, we suggest that in individuals with preserved sensibility magnetic stimulation of the spinal cord with intensities below the pain threshold is ineffective in activating autonomic nerve fibres innervating bladder, bladder neck, and rectum.

Functional magnetic stimulation facilitates gastric emptying

OBJECTIVE

To evaluate the effect of functional magnetic stimulation (FMS) on gastric emptying in able-bodied and spinal cord injury (SCI) subjects.

DESIGN

A prospective, nonrandomized clinical experiment.

SETTING

SCI and disorder center in a Veterans Affairs medical facility.

PARTICIPANTS

Five healthy, able-bodied subjects and 4 subjects with SCI.

INTERVENTION

A commercially available magnetic stimulator was used; a round magnetic coil was placed along the T9 spinous process. The intensity of the magnetic stimulation was 60%, with a frequency of 20 Hz, and a burst length of 2 seconds for the gastric emptying protocol. Man Outcome Measures: Rate of gastric emptying and time required to reach gastric emptying half-time (GE(t1/2)) with and without FMS. Data fit into linear regression curve.

RESULTS

Accelerated gastric emptying was achieved in both able-bodied and SCI subjects. The mean +/- standard error of mean of the GE(t1/2) at baseline and with FMS was 36+/-2.9 minutes and 33+/-3.1 minutes, respectively, for able-bodied subjects, and 84+/-11.1 minutes and 59+/-12.7 minutes, respectively, for SCI subjects.

CONCLUSION

Gastric emptying was enhanced by FMS in able-bodied subjects and was greatly enhanced in SCI subjects. FMS can be a useful noninvasive therapeutic tool to facilitate gastric emptying in humans.

Spinal cord injury medicine. 3. Rehabilitation outcomes

This self-directed learning module highlights rehabilitation outcomes in spinal cord injury (SCI). It is part of the chapter on SCI medicine in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article focuses on the multiple concerns for functional recovery after SCI, chiefly, the potential for ambulation, upper-extremity recovery, options for functional neuromuscular stimulation (FNS), sexual activity, and optimal outcome after a metastatic lesion. Motor incomplete patients have a better prognosis for ambulation than persons with sensory incomplete injury. Positive predictors for ambulation, including pinprick and lower-extremity motor scores greater than 20, are discussed. Meaningful recovery can occur in the upper extremities for at least 1 year. FNS options have been developed to promote functional control of the upper extremities for persons with tetraplegia, phrenic pacing, and bladder continence. A critical component of an individual's expression of self is his/her sexuality; sexual function after SCI is described in detail, including options for treatment of erectile dysfunction and various birth control methods for women. Expectations for an appropriate rehabilitation stay for a person with metastatic SCI differ for an individual with traumatic SCI. Differences may include changing routine pathways and timelines to focus on patient-centered quality of life for transition to home.

OVERALL ARTICLE OBJECTIVE

To identify potential outcomes in ambulation, upper-extremity function, FNS, and sexual function after SCI and after metastatic cancer.

Functional magnetic stimulation facilitates colonic transit in rats

OBJECTIVE

To investigate the effect of functional magnetic stimulation (FMS) on colonic transit in rats.

DESIGN

Experimental.

SETTING

Functional magnetic stimulation laboratory in a Veterans Administration health care system.

ANIMALS

Twenty-four female Wistar rats, divided into an experimental group and a control group.

INTERVENTIONS

All rats had technetium 99m (Tc 99m) infused through a cecal catheter to assess colonic transit times. FMS was performed over the cervical region; a figure of 8 magnetic coil was used in the experimental group. The colon was removed and sectioned into 10 segments, and a stool sample was taken in both groups.

MAIN OUTCOME MEASURES

Distribution of radioactivity within the large intestine and stool were measured.

RESULTS

Geometric center calculations showed significant differences (p <.001) between the control group and the experimental group when the distribution of radioactivity along the colon was measured. The percentage of Tc 99m recovered from the stool in the experimental group was significantly higher than the percentage recovered from the control group.

CONCLUSION

FMS facilitates colonic transit in a rat model.

Functional magnetic stimulation for conditioning of expiratory muscles in patients with spinal cord injury

OBJECTIVE

To evaluate the effectiveness of functional magnetic stimulation (FMS) in conditioning expiratory muscles patients with spinal cord injury (SCI).

DESIGN

A prospective before-after trial.

SETTING

The Functional Magnetic Stimulation Laboratory of the SCI Health Care Group, VA Long Beach Health Care System, and the Spinal Cord Injury Services, Department of Veterans Affairs, Palo Alto Health Care System.

PARTICIPANTS

Eight men with tetraplegia.

INTERVENTION

Expiratory muscle training was achieved by placing a magnetic stimulator with a round magnetic coil along subjects' lower thoracic spine.

MAIN OUTCOME MEASURES

Measures taken were the maximal expired pressure at total lung capacity (MEP-TLC) and at functional residual capacity (MEP-FRC), expiratory reserve volume (ERV), and the forced expiratory flow rate at TLC (FEF-TLC) and at FRC (FEF-FRC) by subjects' voluntary maximal efforts.

RESULTS

After 4 weeks of conditioning, the mean +/- standard error of the mean values were: MEP-TLC, 55.3 +/- 8.6cmH(2)O; MEP-FRC, 29.6 +/- 5.6cmH(2)O; ERV,.57 +/-.08L; FEF-TLC, 4.3 +/- 0.5L/s; and FEF-FRC, 1.9 +/- 0.2L/s. These values correspond to, respectively, 129%, 137%, 162%, 109%, and 127% of pre-FMS conditioning values. When FMS was discontinued for 2 weeks, the MEP-TLC returned to its pre-FMS training value.

CONCLUSION

A 4-week protocol of FMS of the expiratory muscles improves voluntary expiratory muscle strength significantly, indicating that FMS can be a noninvasive therapeutic technology in respiratory muscle training for persons with tetraplegia.