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Introduction: Transcutaneous parasacral nerve stimulation (TPNS) via electrodes placed over the sacrum can activate afferent neuronal networks noninvasively, leading to sacral reflexes that may improve colonic motility. Thus, TPNS can be considered a promising, noninvasive, and safe method for the treatment of constipation. However, there is no published study investigating its use in children with functional constipation. This is a single-center, prospective, longitudinal, and interventional study designed to assess the applicability and clinical outcomes of TPNS in functionally constipated children., Patient Concerns: Parents or guardians of patients will be informed of the purpose of the study and will sign an informed consent form. The participants may leave the study at any time without any restrictions., Diagnosis: Twenty-eight children (7-18 years old) who were diagnosed with intestinal constipation (Rome IV criteria) will be included., Interventions: The patients will be submitted to daily sessions of TPNS for a period of 4 or 8 weeks and will be invited to participate in semistructured interviews at 3 or 4 moments: 1 week before the beginning of TPNS; immediately after the 4 and/or 8 weeks of TPNS; and 4 weeks after the end of the intervention period. In these appointments, the aspects related to bowel habits and quality of life will be assessed., Outcomes: This study will evaluate the increase in the number of bowel movements and stool consistency, the decrease in the number of episodes of retentive fecal incontinence, and the indirect improvement in the overall quality of life., Conclusion: we expect that this study protocol can show the efficacy of this promising method to assist the treatment of children with functional constipation., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2020 the Author(s). Published by Wolters Kluwer Health, Inc.)

Rationale: Anterior spinal meningoceles are rare neuroanatomic abnormality formed by protrusion of the spinal meninges through a defect in the vertebral column. Presently, therapeutic options for anterior spinal meningoceles are still controversial. The objective of this study is to discuss the individualized management of giant anterior spinal meningoceles., Patient Concerns and Diagnoses: We analyzed 4 patients with anterior spinal meningoceles between 2007 and 2014 in our department by retrospective chart review, two of whom were anterior sacral meningoceles (ASMs), and another2 were intrathoracic meningoceles (ITMs)., Interventions and Outcomes: Patients mainly presented with compressive symptoms including rectal irritation, dyspnea (patient 3) and fixed neurologic deficits (patient 4). Three out of 4 patients received surgical treatment, one of which underwent reoperation. After surgery, meningoceles in 1 patient completely disappeared. Two patients acquired the stability of the size of the meningoceles., Lessons: Management of anterior spinal meningoceles often requires precise treatment based on the different conditions of each patient. Surgical intervention has been proposed for the treatment of symptomatic anterior spinal meningoceles. The goal of surgery is to safely disconnect the linkage between the cyst and CSF from subarachnoid space to prevent further enlargement of the cyst or reaccumulating of cystic fluid.

Fecal incontinence, or the involuntary leakage of solid or loose stool, is estimated to affect 7-15% of community-dwelling women (1). It is associated with reduced quality of life, negative psychologic effects, and social stigma (2), yet many women do not report their symptoms or seek treatment. Less than 3% of women who do self-report fecal incontinence will have this diagnosis recorded in their medical record (3). Obstetrician-gynecologists are in a unique position to identify women with fecal incontinence because pregnancy, childbirth, obstetric anal sphincter injuries (OASIS), and pelvic floor dysfunction are important risk factors that contribute to fecal incontinence in women. The purpose of this Practice Bulletin is to provide evidence-based guidelines on the screening, evaluation, and management of fecal incontinence to help obstetrician-gynecologists diagnose the condition and provide conservative treatment or referral for further work up and surgical management when appropriate. For discussion on fecal incontinence associated with OASIS, see Practice Bulletin No. 198, Prevention and Management of Obstetric Lacerations at Vaginal Delivery (4).

Background: This study aimed to perform a systematic literature review of the clinical trial evidence on electrical stimulation for the treatment of neurogenic bowel dysfunction (NBD) after spinal cord injury (SCI)., Methods: Systematic electronic searches were carried out in the PubMed/Medline, EMBASE, Cochrane Central Register of Controlled Trials, and China National Knowledge Infrastructure databases, along with the reference lists in the include studies. Studies were eligible for inclusion if they adopted a controlled clinical design based on human population, the patients suffered from spinal cord injury, the main outcomes were the disorders of bowel function and the intervention was electrical stimulation. Also, the language was limited to English and Chinese., Results: Eleven studies were included in this systematic review, comprising transcutaneous electrical stimulation, transrectal bowel stimulation, sacral nerve stimulation, intravesical electrical stimulation, etc. Of the 11 studies, 3 were randomized controlled trials, 8 were controlled before-and-after trials. The quality of the included studies was moderate bias risk. Most studies revealed that the electrical stimulation was beneficial for the patient with NBD after SCI., Conclusions: Only 11 small clinical studies with 298 participants have evaluated the efficacy of electrical stimulation for NBD after SCI. Although some studies showed electrical stimulation was benefit for the patient with NBD after SCI, there was currently not enough evidence to support the use of electrical stimulation could improve the clinical symptoms of those patients. Thus, well-designed randomized controlled trials with larger patient population are warranted to establish its benefit in clinical practice in the future.

Objectives: The aim of this study was to investigate surgical practice patterns of American urologists treating refractory overactive bladder (OAB) over the past decade. Refractory OAB remains a management challenge to urologists. When multiple medical therapies have failed, treatment options may include sacral neuromodulation (SNM) or surgery such as augmentation cystoplasty (AC)., Methods: Data on SNM and AC performed between 2003 and 2012 by certifying and recertifying urologists were obtained in the form of annualized case logs from the American Board of Urology (ABU). Associations between surgeon characteristics (type of certification, annual volume, practice type, and location) and these procedures were evaluated., Results: Over the past decade, 756 of 6355 urologists certified with the ABU performed SNM or AC for the treatment of refractory OAB. Forty-five (6%) of these surgeons completed fellowships in female urology and 71 surgeons (9%) completed another type of fellowship program. Surgeons recertifying with ABU performed 76% of all SNM procedures. Although SNM and AC have increased from 64 to 2086 between 2003 and 2012, however, this is mainly driven by the increase of SNM from 48 to 2068 cases. Rates of AC have remained stable with 14 to 38 cases reported annually. However, they have declined relative to the total, from 25% in 2003 to less than 1% in 2012., Conclusions: Sacral neuromodulation has increased dramatically over the past decade in surgeons certified with the ABU. This is in contrast to AC, which while remaining stable in number of procedures.

Objectives: The aim of this prospective, randomized, multicenter, single-blind, 4 × 4 crossover study was to estimate the effect of 4 InterStim cycling settings (continuous, 16 seconds on/8 seconds off, 10 minutes on/10 minutes off, and 30 minutes on/23.5 hours off) on efficacy, Global Response Assessment, and safety., Methods: Eligible women implanted for at least 3 months for urgency urinary incontinence (UI) were enrolled, and daily diaries were collected. General linear mixed models were used to estimate the cycling effect on efficacy. Quality of life measured by Global Response Assessment (subjects' perception of effectiveness) and safety were summarized., Results: Primary efficacy analysis was based on the first 24 subjects who completed unique randomization sequences. Mean age was 64 years, and mean implant duration was 2.8 years. Results showed no significant cycling (P = 0.3773) or period (P = 0.0800) effect on UI. There was a statistically significant interaction between cycling and period (P = 0.0032). In the first period, subjects on 10 minutes on/10 minutes off had significantly fewer UI episodes compared with subjects on 16 seconds on/8 seconds off (P = 0.0026); this difference was not observed in any other period or sensitivity analyses. No cycling effect was found on urgency or pad usage. When programmed to 10 minutes on/10 minutes off, 54% of subjects felt their incontinence symptoms improved compared with when they entered the study, followed by 42% on 30 minutes on/23.5 hours off, 38% on 16 seconds on/8 seconds off, and 29% on continuous. Safety was similar across cycling settings., Conclusions: The results suggest that patients with overactive bladder who have been implanted with sacral neuromodulation devices and are receiving substantial benefit may perceive further optimization by switching to cycling settings.

Objective: To simulate sacrospinous ligament fixation on cadaveric specimens, describe the surrounding retroperitoneal anatomy, and estimate the risk to nerves and arteries for the purposes of optimizing safe suture placement., Methods: Sacrospinous ligament fixation was performed on eight fresh-tissue female cadavers using a Capio ligature capture device. Distances from placed sutures to the following structures were measured: ischial spine; fourth sacral root; pudendal nerve; the nerve to coccygeus muscle; the nerve to levator ani muscle; inferior gluteal artery; and internal pudendal artery. Periligamentous anatomy was examined in an additional 17 embalmed cadaver dissections., Results: Sacrospinous ligament length was not seen to differ significantly between sides. The fourth sacral spinal nerve was seen most commonly associated with the medial third of the ligament, whereas the pudendal nerve and the nerves to coccygeus and levator ani muscles were associated with the lateral third. The inferior gluteal artery was seen leaving the greater sciatic foramen a median 15.8 mm (range 1.8-48.0, CI 14.9-22.3) above the ligament, whereas the internal pudendal artery exited just above the ischial spine. The two sets of sutures were placed 20.5 mm (range 9.2-34.4, CI 19.7-24.7) and 24.8 mm (range 12.4-46.2, CI 24.0-30.0) medial to the ischial spine, respectively. No structures were directly damaged by placed sutures. The nerves to coccygeus and levator ani were closest and arteries farthest from the placed sutures., Conclusion: The middle segment of the sacrospinous ligament has the lowest incidence of nerves and arteries associated with it. This study confirms that the nerves supplying the pelvic floor muscles are at a higher risk from entrapment than the pudendal nerve.

Rationale: Trans-sacral epiduroscopic laser decompression (SELD) is reported to have strong positive short-term effects in controlling lower back pain (LBP) or radicular leg pain following herniated lumbar disc (HLD). However, little is known about the possible complications following SELD., Patient Concerns: A 36-year-old man received SELD with YAG laser for controlling LBP and radicular pain due to HLD on L5-S1. However, after SELD, voiding and defecation difficulties and sensory deficits on the S3-5 dermatome were presented., Diagnoses: An areflexic neurogenic bladder was demonstrated by a urodynamic study four days after onset of sacral nerve root injury symptoms. In the electromyogram study, latency of electrically induced bulbocavernosus reflex (BCR) was delayed on both sides at four days after symptom onset. Based on the patient's symptoms and the results of the clinical evaluation, we diagnosed the patient as having an injury in the sacral nerve roots., Interventions: The patient was observed without any specific medication., Outcomes: Three months after symptom onset, the patient's voiding and defecation difficulties were nearly completely recovered., Lessons: In this study, we described a patient who showed neurogenic bladder and bowel and sensory deficits in the S3 to S5 dermatome due to sacral nerve root injury after SELD. During SELD, clinicians should be mindful of the possibility of injury to sacral nerve roots.

Objective: To evaluate functional and morphometric magnetic resonance neurography of the dorsal root ganglion and peripheral nerve segments in patients with Fabry painful neuropathy., Methods: In this prospective study, the lumbosacral dorsal root ganglia and proximal peripheral nerve segments of the lower extremity were examined in 11 male patients with Fabry disease by a standardized 3T magnetic resonance neurography protocol. Volumes of L3 to S2 dorsal root ganglia, perfusion parameters of L5-S1 dorsal root ganglia and the spinal nerve L5, and the cross-sectional area of the proximal sciatic nerve were compared to healthy controls., Results: Dorsal root ganglia of patients with Fabry disease were symmetrically enlarged by 78% (L3), 94% (L4), 122% (L5), 115% (S1), and 119% (S2) ( p < 0.001). In addition, permeability of the blood-tissue interface was decreased by 53% ( p < 0.001). This finding was most pronounced in the peripheral zone of the dorsal root ganglion containing the cell bodies of the primary sensory neurons ( p < 0.001). Spinal nerve permeability showed no difference between patients with Fabry disease and controls ( p = 0.7). The sciatic nerve of patients with Fabry disease at the thigh level showed an increase in cross-sectional area by 48% ( p < 0.001)., Conclusions: Patients with Fabry disease have severely enlarged dorsal root ganglia with dysfunctional perfusion. This may be due to glycolipid accumulation in the dorsal root ganglia mediating direct neurotoxic effects and decreased neuronal blood supply. These alterations were less pronounced in peripheral nerve segments. Thus, the dorsal root ganglion might play a key pathophysiologic role in the development of neuropathy and pain in Fabry disease., (© 2017 American Academy of Neurology.)

Implanted electronic medical devices. or stimulators such as pacemakers and nerve stimulators have grown enormously in diversity and complexity over recent decades. The function and potential interaction of these devices with the perioperative environment is of increasing concern for anesthesiologists and surgeons. Because of the innate electromagnetic environment of the hospital (operating room, gastrointestinal procedure suite, and imaging suite), implanted device malfunction, reprogramming, or destruction may occur and cause physical harm (including nerve injury, blindness, deafness, burn, stroke, paralysis, or coma) to the patient. It is critical for the anesthesiologist and surgeon to be aware of the function and interaction of implanted devices, both with other implanted devices and procedures (such as magnetic resonance imaging and cardioversion) in the hospital environment. Because of these interactions, it is imperative that proper device function is assessed when the surgical procedure is complete. This review article will discuss these important issues for 12 different types of "little black boxes," or noncardiac implantable electronic medical devices.

Study Design: Cross-section analysis., Objective: A quality-of-life oriented scoring system for evaluation of lower limbs, bladder, and bowel functions of patients after sacral tumor resection has been proposed and was adopted in a clinical research., Summary of Background Data: Surgical resections of sacral tumors usually cause postoperative neurologic deficits. A widely agreed scoring system for detailed evaluation of functional outcomes is not yet established., Methods: The scoring system has three domains with three items in each domain, being allocated 0 to 3 points of each item according to the degree of functional impairment. Overall function scale is presented in percentage form. In the current single-center cross-section study, it was adopted to evaluate and quantify the postoperative functional outcomes of 170 consecutive patients who underwent sacrectomy., Results: Significant observer agreement (P < 0.01) was found in all nine items of the proposed system. Detailed functional outcome and difference between each group can be well described by the scoring results. Preservation of bilateral S1 nerve roots preserved majority of motor and sensory function in lower limbs. The probability and degree of urine incontinence (P = 0.003) and abnormal bladder sensation (P = 0.039) was significantly lower in patients with bilateral S3 nerve preserved than those whose unilateral S3 was severed. Patients with unilateral S3 preserved had a lower incidence and degree of dysuria (P = 0.056), constipation (P = 0.059), bowel incontinence (P = 0.007), and abnormal rectal sensation (P = 0.002) than those whose bilateral S3 were sacrificed. Functional outcomes for patients with retained coccyx were better than those with coccyx transected. Functional outcome of different level sacral nerve preservation was semi-quantified and profiled., Conclusion: Detailed and intuitive description of neurologic deficits after sacral tumor resection is the major purpose of current scoring system. The ease of use and reproducibility makes it a practical tool to evaluate function status after sacrectomy under oncologic condition., Level of Evidence: 4.

Background: Urinary voiding dysfunction is reported in many patients with complex regional pain syndrome (CRPS). However, there is a gap in the literature for treating patients with CRPS who develop incontinence symptoms., Case: We report a case describing the use of sacral neuromodulation therapy in a patient with urgency urinary and fecal incontinence who had a previously implanted spinal cord stimulator for type 1 CRPS, formerly known as reflex sympathetic dystrophy. Despite initial hesitation and treatment delay, sacral neuromodulation therapy was successful and effective in controlling both fecal and urgency urinary incontinence symptoms for the patient. This intervention continues to provide her with an improved quality of life 10 months after her procedure., Conclusions: In this case, there was significant hesitation from the provider and patient to use invasive treatments for incontinence symptoms when the patient's pain symptoms have been well controlled with an existing spinal device. However, in this patient with type 1 CRPS, even in the setting of an existing spinal cord stimulator, sacral neuromodulation therapy was an effective treatment.

Introduction: The potential for costimulation with competitive effects between implanted electronic devices remains speculative both at the level at the implanted device and with active programming but also at the retrograde site of action. We present a patient with an implanted vagal nerve stimulator for refractory epilepsy who underwent successful staged sacral neuromodulation (SNS) and benefits from both technologies., Case: This is a case report of a 42-year-old female patient with a history notable for medically intractable epilepsy, temporal lobectomy, and vagal nerve stimulation who subsequently underwent staged SNS for refractory overactive bladder syndrome. The patient continues to benefit from sustained reduction in her bladder issues and without dimunition of her seizure threshold at 6-month follow-up., Discussion: Different action sites for SNS as well as vagal nerve stimulation are possible. The role of the thalamus in continence and seizure activity is reviewed. There does not seem to be an interactive effect during the simultaneous use of these 2 modalities.

Objectives: The aim of this study was to identify risk factors for surgical site infection in patients undergoing sacral nerve modulation (SNM) surgery., Methods: We conducted a retrospective cohort analysis of 290 patients undergoing a total of 669 SNM procedures between 2002 and 2012 by 2 fellowship-trained female pelvic medicine and reconstructive surgery attending physicians at the University of California-Irvine Medical Center. Infection was defined as a charted abnormal examination finding at the implantation site (erythema, induration, purulent discharge) resulting in prescription of antibiotics, hospitalization, or explantation. We extracted information from the medical record regarding possible risk factors for infection including age, body mass index, immunosuppression (diabetes mellitus, chronic steroid use, smoker, chemotherapy), number of procedures per patient, and number of days between stages 1 and 2. In addition, we compared infection rates before and after 2008 when a clinical practice change was made with the implementation of home chlorhexidine washing (CHW) prior to SNM surgery., Results: Thirty infections occurred, 25 of which were managed with oral antibiotics. Nine required intravenous antibiotics, and 11 required removal of the implanted device. Three patients experienced infection on 2 separate occasions. Seventeen infections had culture data available. Nine of the patients who underwent explantation had wound cultures positive for methicillin-resistant Staphylococcus aureus.Thirteen of the 26 patients who developed infection had medical histories significant for immunosuppression. Three patients developed late-onset abscess formation at 234, 257, and 687 days after stage 2, respectively. The median time between the most recent SNM procedure and development of infection was 14 days (range, 6-88 days).Body mass index and immunosuppression were significant predictors of infection, whereas age, parity, indication for procedure, and number of days between stages 1 and 2 were not found to be independent predictors. Three hundred twenty-three procedures were performed prior to and 346 procedures were performed after institution of home CHW. Twenty-four (80%) of the 30 reported infections were prior to CHW, whereas only 6 infections (20%) occurred after this change in practice. Prior to institution of CHW, the infection rate was 7.4%, and after institution of CHW, it was 1.7% (P = 0.002). Of the 83 patients with compliance data available for CHW use, 71 reported using CHW, whereas 12 reported not using CHW., Conclusions: Surgical site infection is a significant risk of SNM surgery, although our infection rate is lower than previously reported. Chlorhexidine washing appears to reduce the risk of infection in this population. Because the majority of infections requiring explantation were methicillin-resistant S. aureus positive, prophylactic treatment for this organism should be considered as an additional strategy to reduce infection. Body mass index and immunosuppression appear to be independent risk factors for infection.

Originally described in 1982, scalp somatosensory evoked potential responses can be recorded after stimulation of multiple different pudendal nerve- and sacral root-supplied structures. The resulting P40 response is usually the highest amplitude at Cz. Responses are generally easy to resolve and therefore should be of equivalent ease to follow for neurophysiologic intraoperative monitoring versus lower limb peripheral nerve somatosensory evoked potentials (e.g., tibial or fibular [peroneal] nerves), but sizeable reports of pudendal somatosensory evoked potential monitoring are few. Direct orthodromic sensory nerve action potential recording from the cauda equina in response to single such sacral stimuli has been reported of utility for preserving roots that participate in urinary control during dorsal rhizotomy procedures for spasticity. Technical application of both techniques is quite straightforward. As in most areas of neurophysiologic intraoperative monitoring, there are no well-constructed historical control series informing use of these techniques and, certainly, no clinical trials. Given the socially devastating consequences of urinary and anal continence disturbances and a fairly high rate of functional postoperative disturbances when sacral roots are manipulated, this field begs more active clinical investigation.

Aims: To determine the correlation of InterStim amplitudes required to evoke motor and sensory responses in subjects with overactive bladder (OAB) and to determine if subjects reprogrammed to achieve motor response have improvement in voiding diary parameters., Methods: Descriptive pilot study of patients with an existing sacral nerve stimulation (SNS) device for OAB. Subjects completed voiding diaries and reported subjective improvement at current settings. Subject's implantable pulse generator was interrogated while surface electromyography (EMG) was performed using a rectal sponge electrode. Electromyography was evaluated for baseline motor response demonstrated by compound muscle action potential (cMAP) at current settings. Stimulation amplitude was reduced to zero then incrementally increased. Amplitudes evoking subject sensation and motor response were recorded and used for correlation calculation. Subjects without baseline motor response were reprogrammed to achieve cMAP, and voiding diaries were completed after reprogramming., Results: Thirty-one subjects were recruited. Twelve (39%) had motor response (cMAP) at baseline settings. Subjects with motor response were significantly more likely to report sensation of stimulation versus those without (55% vs 17%; P = 0.04). Amplitudes evoking motor response were found to be significantly correlated to those for sensory response (r = 0.90; P < 0.0005). Sixteen of 19 subjects without baseline motor response were successfully reprogrammed to achieve cMAP. Improvements in nocturia, incontinence, and urgency incontinence episodes (14.4%, 19.8%, 18.2%; nonsignificant) were seen in the reprogrammed group., Conclusion: Sacral nerve stimulation motor and sensory amplitudes were highly correlated in our cohort, and subjects with motor response were significantly more likely to feel sensation of stimulation. This supports the theory that both motor efferent and sensory afferent portions of the sacral nerve may contribute to SNS mechanism.

Background and Objective: : Stimulation amplitude used in sacral nerve stimulation (SNS) is at or just above the sensory threshold (ST). This randomized, blinded crossover study aimed to document if stimulation at 75% or 50% of the ST would be as effective as stimulation at the ST for fecal incontinence (FI)., Method: : FI patients treated with SNS, who were satisfied with current treatment results and had a minimum symptom reduction of 75%, were eligible. Patients were randomized into 3 periods of 4-week stimulation: ST, 75% of the ST, and 50% of the ST. Patients completed a bowel habit diary and questionnaires on bowel functions and patient satisfaction at the study baseline and in each study period., Results: : Nineteen patients (18 females) with a mean follow-up of 51.7 ± 29.9 months were included from January to April 2010. The mean FI episodes per 3 weeks decreased from pre-SNS therapy 33.6 ± 31.6 to 1.1 ± 2.2 at the study baseline (P < 0.001). Decreasing the stimulation amplitude to as low as 50% of the ST did not affect the overall number of incontinent episodes (P = 0.078). The Wexner incontinence score dropped from 16.5 ± 2.5 for pre-SNS therapy to 7.4 ± 3.1 at the study baseline (P < 0.001). Decreasing the stimulation amplitude to ST, 75% of the ST or 50% of the ST, did not change the Wexner score when compared with the study baseline (P = 0.581). In general, patient satisfaction was high at the study baseline and did not deteriorate as the stimulation amplitude was decreased to 50% of the ST (P = 0.932)., Conclusions: : Subsensory stimulation as low as 50% of the ST is as effective as stimulation at or above the ST. The study was approved by the Regional Committee on Biomedical Research Ethics, Denmark, and registered at ClinicalTrials.gov (NCT01130870).

Objective: A case is presented in which a 58-year-old man developed a potential unintended and durable treatment of pain at remote sites (cervical region and low back) after sacral nerve stimulation for chronic urinary retention., Methods: Proper placement of the electrodes in the S3 foramen was confirmed by physiological response and fluoroscopy., Results: Potential causality was shown by recurrent pain with the stimulators turned off and abatement of pain with the stimulators turned on., Discussion: The current case presents a potential example of neurological crosstalk and highlights the inherent complexity in human neural physiology. Further research may reveal novel treatment strategies for patients with voiding dysfunction and chronic pain syndromes.

Objective: Prospective randomized double-blind placebo-controlled crossover trial of 14 female patients (median age 52 [30-69] years) with proctographically defined evacuatory dysfunction (ED) and demonstrable rectal hyposensitivity (elevated thresholds to balloon distension in comparison with age- and sex-matched controls)., Background: Sacral nerve stimulation (SNS) is an evolving treatment for constipation. However, variable outcomes might be improved by better patient selection. Evidence that the effect of SNS may be mediated by modulation of afferent signaling promotes a role in patients with ED associated with rectal hyposensation., Methods: SNS was performed by the standard 2-stage technique (temporary then permanent implantation). During a 4-week period of temporary stimulation, patients were randomized ON-OFF/OFF-ON for two 2-week periods. Before insertion (PRE), and during each crossover period, primary (rectal sensory thresholds) and secondary (bowel diaries, constipation, and GIQoL [gastrointestinal quality of life] scores) outcome variables were blindly assessed., Results: Thirteen patients completed the trial. Following stimulation, defecatory desire volumes to rectal balloon distension were normalized in 10 of 13 patients (PRE: mean 277 mL [234-320] vs ON: 163 mL [133-193] vs OFF: 220 mL [183-257 mL]; P = 0.006) and maximum tolerable volume in 9 of 13 (PRE: mean 350 mL [323-377] vs ON: 262 mL [219-305] vs OFF: 298 mL [256-340 mL]; P = 0.012). There was a significant increase in the percentage of successful bowel movements (PRE: median 43% [0-100] vs ON: 89% [11-100] vs OFF: 83% [11-100]; P = 0.007) and Wexner constipation scores improved (PRE: median 19 [9-26] vs ON: 10 [6-27] vs OFF: 13 [5-29]; P = 0.01). There were no significant changes in disease-specific or generic quality of life measures. Eleven patients progressed to permanent stimulation (9/11 success at 19 months)., Conclusions: Most patients with chronic constipation secondary to ED with rectal hyposensitivity responded to temporary SNS. The physiological results presented support a mechanistic role for rectal afferent modulation.

Purpose of Review: Anorectal dysfunction constitutes a major problem in patients surviving rectal cancer. In this review, the current options for management of fecal incontinence after treatment for rectal cancer are discussed., Recent Findings: First line therapy should be conservative measures aimed at symptomatic control. Dietary regiments, fibers, constipating agents and enemas may be tried. Biofeedback is an option to strengthen the external anal sphincter, improve rectal sensitivity and coordinate pelvic floor muscles. Colonic irrigation has been successful to reduce symptoms and improve quality of life. Surgical interventions may be considered if conservative management fails. Sacral nerve stimulation is a successful minimal invasive procedure for the treatment of fecal incontinence; however, evidence of the method after treatment for rectal cancer is still limited. Complex surgical procedures should be limited to only highly selected patients. A stoma should be considered when other treatment modalities have failed., Summary: Systematic evaluation of the postoperative anorectal function in patients treated for rectal cancer should be a standard practice at every follow-up. An individually tailored treatment should be offered to the severely affected patients to minimize their symptoms. The evidence on the most commonly used treatments is sparse, therefore, further randomized controlled studies are needed.

A patient with muscle cramps was referred for nerve conduction studies and electromyography. Her study demonstrated bursts of spontaneous electromyography activity, which waxed and waned in amplitude with a "dive bomber"-like sound. The abnormal finding was found to be an artifact from an implanted sacral nerve stimulator for bladder incontinence.

Objective: Electromyographers must reliably differentiate between H reflexes and F waves when recording from the soleus muscle in the evaluation of S1 radiculopathy. The use of F waves in root-level injuries is questioned, whereas H reflexes have shown value in the evaluation of S1 radiculopathy. We studied the relationship between the tibial H reflex and F wave latencies in the limbs of 40 subjects., Design: After recording the H wave latency, we changed the gain to 200 microV/cm and increased the stimulation to supramaximal for ten additional responses without moving the recording or stimulating electrodes. We also calculated the predicted H wave latency with the standard formula. Forty subjects, mean age 32 yr, consented and participated., Results: The mean of the average F wave was 1.76 ms longer than the ipsilateral H reflex latency. The mean side-to-side difference of the average F wave was 0.56 ms. The H reflex latency side-to-side difference was 0.36 ms., Conclusion: The findings suggest that the average F wave latencies have a predictive value in the clinical context similar to the H reflex.

Study Design: A case report of a man with a gigantic cellular schwannoma in the sacrum treated with high sacral amputation accompanied by careful nerve root-sparing dissection., Objectives: To describe the atypical clinical course of an intrasacral cellular schwannoma and the surgical procedure of high sacral amputation performed in a way to prevent needless sacrifice of functionally essential nerve roots., Summary of Background Data: Fundamentally, a cellular schwannoma is a benign tumor, but the clinical course is atypical. The symptoms are mild and the clinicopathologic features often mislead us to make a diagnosis of malignancy. The occurrence rate of intraosseous cellular schwannoma was reported to be 0.2% of all bony tumors, and the main location was the retroperitoneal space in the pelvis. Forty-one cases of giant intrasacral schwannomas have been reported so far. Among them, large sacral schwannoma with anterior cortex erosion and associated intrapelvic extension was extremely rare., Methods: The patient presented with a 5-year history of right leg and buttock pain, which did not disturb his daily activities. After a histopathologic diagnosis and a complete set of image studies, high sacral amputation with preservation of uninvolved nerve roots was performed at S1-S2 through a combined anterior and posterior approach. Both S1 nerve roots and the right S2-S3 nerve roots were saved using a threaded saw. The lumbar spine was stabilized to the pelvic girdle using spinal instrumentation with posterolateral fusion., Results: Eighteen months after the tumor was resected the patient had a very good clinical outcome, and there were no radiologic signs of instability or recurrence of the tumor. Locomotor function of both lower extremities and bowel and urinary functions were well maintained. The patient returned to his previous work., Conclusions: High sacral amputation following a combined anteroposterior approach provided good results without causing any disability. A detailed preoperative planning and careful dissection of uninvolved nerve roots prevented unnecessary neurologic impairment in locomotion and the detrusor and anorectal function.

Objective: To characterize the longer-term therapeutic response of permanent sacral nerve stimulation for fecal incontinence and to delineate suitable indications and the mode of action., Summary Background Data: A single report of permanent sacral nerve stimulation in three patients followed up for 6 months showed marked improvement in fecal continence. Acute evaluation has shown that the effect may be mediated by altered rectal and anal smooth muscle activity, and facilitation of external sphincter contraction., Methods: Five women (age 41-68 years) with fecal incontinence for solid or liquid stool at least once per week were followed up for a median of 16 months after permanent implantation. All had passive incontinence, and three had urge incontinence. The cause was scleroderma in two, primary internal sphincter degeneration in one, diffuse weakness of both sphincters in one, and disruption of both sphincters in one., Results: All patients had marked improvement. Urgency resolved in all three patients with this symptom. Passive soiling resolved completely in three and was reduced to minor episodes in two. Continence scores (scale 0-20) improved from a median of 16 before surgery to 2 after surgery. There were no early complications, and there have been no side effects. One patient required wound exploration at 6 months for local pain, and a lead replacement at 12 months for electrode displacement. The quality of life assessment improved in all patients. The resting pressure increased in four patients, but there was no consistent measured physiologic change that could account for the symptomatic improvement., Conclusions: In patients with sphincter degeneration and weakness, and possibly in those with sphincter disruption, sacral nerve stimulation markedly improves fecal incontinence.

Study Design: A test-retest design was used to assess the reproducibility of position sense measurements of the spine recorded at T1, T7, L1, and S2., Objectives: To measure position sense at four spinal levels in healthy volunteers and to determine if this varies on a day-to-day basis. The overall purpose is to provide baseline data for studying position sense of the spine in patients with spinal lesions., Summary of Background Data: Position sense, which is one component of proprioception, is assessed by the ability to reposition the body after displacement. In peripheral joints, position sense is accurate to within a few degrees. Studies on the spine suggest similar accuracy, but most have used indirect methods of measurement that often incorporate unusual extraneous cues., Methods: Spinal position sense was assessed in 20 healthy volunteers using an electromagnetic movement sensor system, the 3-Space Fastrak (Polhemus, Colchester, VT), to measure absolute error in actively reproducing upright and flexed positions during movements in both coronal and sagittal planes. Three randomized measurements were taken for each position in one testing session, and measurements were repeated in all participants 2 weeks later., Results: Same-day measurements indicate that spinal position sense is reproducible in upright postures to within a mean of 3.79 +/- 2.56 for movements in the sagittal plane and 2.26 +/- 1.59 degrees for movements in the coronal plane. Corresponding measurements for flexed postures are 5.27 degrees +/- 3.47 degrees and 3.70 +/- 2.62 degrees, respectively. Intraclass correlation coefficients between repeated measurements are generally good in the sagittal plane but are affected by side dominance in the coronal plane. Also, repositioning errors tend to increase on ascending the spine. Repeat measurements taken 2 weeks later show similar values., Conclusions: 1) Healthy volunteers were able to reposition their spine with considerable accuracy as measured with the 3-Space Fastrak; 2) this ability does not change significantly on a day-to-day basis; and 3) the 3-Space Fastrak offers a noninvasive and accurate method for the measurement of spinal position sense.

Objective: A canine model was designed to evaluate the feasibility of stimulus-evoked electromyographic (EMG) monitoring of the lumbosacral nerve roots during the insertion of iliosacral implants., Study Design/methods: Four 2.5-millimeter Kirschner wires (K-wires) were percutaneously inserted under general anesthesia into the S1 body of each of five dog hemipelves using C-arm fluoroscopy image-intensifier control in an actual attempt to compromise the S1 canal and the S1 nerve root. A searching current of twenty milliamperes was initially applied to the K-wire with monitoring electrodes placed in the gastrocnemius muscle. Current thresholds required to evoke an EMG response were recorded for each K-wire. Actual K-wire location was determined by anatomical dissection., Results: Evaluation of these twenty wires revealed that current threshold was directly related to the proximity of the K-wire to the nerve root, with a correlation coefficient of 0.94 (p < 0.001)., Conclusions: Stimulus-evoked EMG monitoring provided reliable data indicating the proximity of the iliosacral implants to the sacral nerve root. This method of intraoperative nerve monitoring could potentially decrease the risk of iatrogenic nerve root injury during pelvic ring surgery. Further study is warranted.

Pudendal nerve evoked potentials were used in orthopaedic surgical procedures involving fixation below the S1 level. Pudendal nerve stimulation was used to monitor 154 patients. Eleven patients (7.14%) had responses that were either difficult or impossible to interpret in that they were not consistently replicable. In one case (0.65%), responses were lost during surgery, and there were no subsequent neurologic sequelae (false-positive response). No patients had postoperative deficit to the sacral roots or to the global cord. Although it is possible to obtain definitive dermatomal responses down to S1, the use of pudendal nerve stimulation was found to provide additional means of monitoring lower sacral roots. Since the pudendal nerve is intimately associated with bowel, bladder, and sexual dysfunction, easily obtainable routine monitoring of this nerve can provide significant safety that the conventional somatosensory and dermatomal responses give to higher spinal levels.

The anatomy of 54 pairs of lumbosacral nerve roots was described in nine fresh adult cadaver specimens, with particular attention given to the fixation of the nerve roots to surrounding skeletal and ligamentous structures in the lumbar spine. Dural ligaments were identified fixing the dura and nerve roots at their exit from the main dural sac to the posterior longitudinal ligament and vertebral body periosteum proximal to the intervertebral disc. Distal fixation occurs at the intervertebral foramen where the epineural sheath of the spinal nerve is attached. The overall arrangement is one which tends to hold the exiting nerve root anteriorly in the spinal canal. Mechanical analysis of this anatomical arrangement explains how pressure can be applied to the extrathecal nerve root by a disc protrusion without compression of the nerve root against the posterior elements. The possible role of the dural ligaments in the pathogenesis of the sciatica syndrome is discussed.

Evidence based on electrical studies is presented for the standard and anomalous patterns of innervation of muscles supplied by the fifth lumbar and first sacral nerve roots. Although considerable controversy still exists, previous work in this field suggests that the L5 nerve root supplies tibialis anterior, extensor hallucis longus, extensor digitorum brevis, and the lateral head of gastrocnemius, while the S1 nerve root innervates the medial head of gastrocnemius, soleus, and abductor hallucis. In order to confirm the reliability of this data, the L5 and S1 nerve roots of 50 patients were electrically stimulated during surgery, and distally evoked responses in the relevant muscles were recorded, using surface electrodes. The results confirm the essential reliability of the proposed table of segmental innervation and also demonstrate that most muscles have a dual innervation, with one nerve root being dominant. However, eight patients (16%) exhibited a marked departure from the normal pattern. For example, it is clear that on occasion the extensor digitorum brevis and the lateral head of gastrocnemius can be supplied by S1 and the soleus and medial head of gastrocnemius can be supplied by L5. In a prospective study of 100 patients presenting with clinical evidence of lumbosacral nerve root entrapment, the level of nerve root involvement, as predicted by electromyography, was compared with the operative findings. Correct preoperative nerve root localization was achieved in 84%.(ABSTRACT TRUNCATED AT 250 WORDS)

A detailed description is given of the principles and surgical technique for extensive resection of the sacrum, including an adjacent part of each ilium, for radical removal of tumor. Two levels of sacral amputation are discussed: between S1 and S2 (through the canals of the S1 nerves) and through S1 (above the canals of the S1 nerves), with or without inclusion of the rectum in the specimen. The former level permits the preservation of the S1 nerves; the latter does not. Important pathoanatomic facts are discussed. The effects of these operations on the urogenital and anorectal function and on the stability of the pelvic girdle are briefly reviewed. Five illustrative cases are reported with comments on the results.

From 1973 to 1981, 94 patients suffering from low-back pain, with or without spread into the lower extremities, were candidates for therapeutic spinal cord stimulation. The etiology of pain in all cases was lumbosacral spinal fibrosis due to multiple myelographies and surgical interventions on the lumbar spine. The long-term results, based on a four-year follow-up, reveal a 60% subjective improvement of pain, a 40% substantial reduction of medication, and a 26% increase in working capacity. The concept of spinal arachnoiditis is reviewed and the term lumbosacral spinal fibrosis proposed. The treatment of this chronic painful and disabling disease is discussed.