External Anal Sphincter Electromyography Research Articles

Impact of Activity-Based Training on Bowel Function in a Rat Model of Spinal Cord Injury.

Significant bowel-related issues after spinal cord injury (SCI) that affect morbidity and quality of life (QOL) include diminished bowel motility, loss of sphincter control, gastric ulcers, autonomic dysreflexia, pain, diarrhea, constipation, and fecal incontinence. Clinical diagnoses and research in humans have largely relied on anorectal manometry (ARM) procedures to increase understanding of the functional effects of SCI on colorectal motility and defecation physiology. Recent pre-clinical rodent studies have also used ARM to further our understanding of bowel-related dysfunctions post-SCI. In the present study, the benefits of different activity-based training (ABT) durations on bowel function were examined. Six groups of male rats including two non-training (NT; uninjured and SCI) and four ABT (quadrupedal [Quad or Q] stepping on a treadmill) groups. All ABT animals received 4 weeks of 1-h daily stepping beginning 2 weeks post-SCI followed by variable amounts for 4 additional weeks (none; daily; once a week; daily for final 4th week only). Outcome measures included fecal output (home cage; metabolic cage) throughout the study and terminal measurements (post 8-week ABT) of external anal sphincter (EAS) electromyography, resting anorectal pressure, and giant contraction (GC) activation under urethane anesthesia. The results indicate that treadmill training normalized defecation amount based on feces weight and food intake, as well as GC frequency, EAS latency and amplitude during fecal expulsion, and resting pressure in specific areas within the colorectum. The two intermittent training groups consistently showed recorded metrics comparable to the non-injured group. The results demonstrate bowel dysfunction in the rodent SCI contusion model with improvements in functional outcomes following ABT. Importantly, the benefits to bowel-related functions with versus without intermittent ABT illustrate the need for periodic therapy to maintain the functional gains of ABT.

Sacral Tarlov cysts: Neurophysiology abnormalities and correlation with pelvic sensory and visceral symptoms.

Recent studies suggest a possible association between Tarlov cysts (TCs), usually considered as incidental radiological findings, and neurological symptoms such as pain, numbness and urogenital complaints. The aim was to explore the relationship between TCs and sacral nerve root functions using pelvic neurophysiology tests, and to correlate changes with clinical symptoms and magnetic resonance imaging (MRI) findings. Consecutive patients with sacral TCs, referred for pelvic neurophysiology testing and presenting with at least one symptom related to the pelvic area, participated in a cross-sectional review of symptoms using validated questionnaires. Findings of pelvic neurophysiology (pudendal sensory evoked potentials, sacral dermatomal sensory evoked potentials, external anal sphincter electromyography) and urodynamics testing were collected retrospectively. The relationship between neurophysiology, MRI findings and patients' symptoms was assessed using Fisher and ANOVA tests. Sixty-five females were included (mean age 51.2 ± 12.1 years). The commonest symptom was pain (92%). Urinary (91%), bowel (71%) and sexual (80%) symptoms were also frequently reported. Thirty-seven patients (57%) had abnormal neurophysiology findings reflecting sacral root dysfunction. No association was seen between MRI findings (size, location of the cysts, severity of compression) and neurophysiology. A negative association was observed between neurophysiology abnormalities and occurrence of urgency urinary incontinence (p = 0.03), detrusor overactivity (p < 0.01) and stress urinary incontinence (p = 0.04); however, there was no association with voiding difficulties. Contrary to current understanding, TCs are associated with injury to the sacral somatic innervation in the majority of patients with presumed symptomatic cysts. However, urinary incontinence is unlikely to be related to TC-induced nerve damage.

Value of electrophysiological indicators in differential diagnosis of parkinson's disease and multiple system atrophy

BackgroundWe evaluated the value of electrophysiological indicators by external anal sphincter electromyography (EAS-EMG), sympathetic skin response (SSR), R-R interval variation (RRIV), and Bulbocavernosus Reflex (BCR) in differential diagnosis of multiple system atrophy (MSA) and Parkinson’s disease (PD).MethodsA total of 41 patients with MSA and 32 patients with PD were enrolled. The electrophysiological changes of autonomic dysfunction were assessed with BCR, EAS-EMG, SSR, and RRIV, and the abnormal rate of each indicator was calculated. The diagnostic value of each indicator was analyzed with ROC curve.ResultsThe incidence rate of autonomic dysfunction in MSA group was significantly higher than that in PD group (p < 0.05). The abnormal rates of BCR and EAS-EMG indicators in MSA group were higher than those in PD group (p < 0.05). The abnormal rates of SSR and RRIV indicators in MSA group and PD group were high; however, there was no significant difference between MSA and PD groups (p > 0.05). The sensitivity of BCR combined with EAS-EMG indicators in differential diagnosis of MSA and PD were 92.3% in males and 86.7% in females, respectively, and the specificity was 72.7% in males and 90% in females, respectively.ConclusionsCombined analysis of BCR and EAS-EMG has high sensitivity and specificity for differential diagnosis of MSA and PD.

Electromyography of the External Anal Sphincter during Micturition and Electrophysiological Bulbocavernosus Reflex in Healthy Spayed Female Canines.

This study aimed to find methods and interferences and illustrate the pattern of external anal sphincter (EAS) electromyography (EMG) during micturition and to determine reference intervals of electrophysiological bulbocavernosus reflex (EBCR) by using robust statistical methods in healthy spayed female canines. Ten healthy spayed female canines (no breed restriction) with a body weight of 11.3-18 kg were enrolled. EAS EMG during micturition and the EBCR test were performed under light general anesthesia. Altogether 25 out of 34 EAS EMG showed a similar pattern, including low-amplitude high-frequency bursting pattern before voiding, medium- or high-amplitude low-frequency bursting pattern at the beginning of voiding, oscillate medium- and/or high-amplitude low-frequency bursting with a low-amplitude high-frequency bursting pattern during voiding, and high-amplitude high-frequency bursting pattern at the end of voiding. An average of 100 consecutive stimulations of EBCR for one cycle were performed in each dog and another cycle was repeated to ensure reproducibility. The lower and upper limits of the reference interval of EBCR onset latency values and EBCR mean amplitude values were calculated using both standard and robust methods with untransformed and transformed Box-Cox data. The EBCR onset latency was between 13.85 and 27.44 milliseconds, whereas the EBCR mean baseline to peak amplitude was not transformed with Box-Cox transformation. All EBCR compound muscle action potentials started with a negative sharp wave, which tapers from the baseline in the upward direction, showing an upturned bell-shaped curve. In conclusion, this study was possibly the first to examine the method and provide the electrographic pattern of EAS EMG during micturition and reference intervals of EBCR onset latency in spayed female dogs, which may serve as baseline information to help veterinarians differentiate healthy from diseased dogs. Further studies should compare normal dogs and dogs with lower urinary tract abnormalities at different lesion locations.

Characteristics of Anal Sphincter Electromyography in Patients with Multiple System Atrophy

In this study, the characteristics of external anal sphincter electromyography (EAS-EMG) in patients with multiple system atrophy (MSA) were analyzed, and its value in the diagnosis of MSA was discussed. The data of 23 patients with MSA who underwent EAS-EMG examination between January 2019 and December 2021 were selected to analyze examination data such as the average duration of motor unit potentials (MUPs), average amplitude, satellite potentials, and the percentage of polyphasic waves, and to explore the correlation between the results of EAS-EMG and autonomic dysfunction in patients with MSA based on their data characteristics. The results of data analysis showed that the most common symptoms in 23 patients with MSA were urination and defecation disorders, sleep disorders, and unsteady walking, the most common signs were increased muscle tone, postural hypotension, and ataxia, and the most common autonomic dysfunction was rectal and bladder dysfunction, orthostatic hypotension, and sexual dysfunction. The average duration of MUPs was 11.6 (10.1-13.9) ms, the average amplitude was 885 (683-1198) μV, and the percentage of polyphasic waves was 26.2 (12.5-50.0)%. Patients with satellite potentials had longer disease duration. There were no significant differences in parameters between different types of autonomic dysfunction. The results suggested that abnormal changes in EAS-EMG may indicate an impaired autonomic function in patients with MSA, and this conclusion may not limit to patients with urination and defecation disorders.

The High Value of External Anal- and Urethral-Sphincter Electromyography in Differential Diagnosis with MSA-P, PD, and PSP.

It is a challenge to differentiate multiple system atrophy parkinsonism (MSA-P), Parkinson's disease (PD), and progressive supranuclear palsy (PSP). We aimed to explore the value of external anal-sphincter electromyography (EAS-EMG) and urethral-sphincter electromyography (US-EMG) in differential diagnosis with MSA-P, PD, and PSP. A total of 149 subjects, including 27 MSA-P, 100 PD, and 22 PSP, were recruited. The average duration and amplitude of motor unit potentials (MUPs), percentage of polyphasic MUPs, amplitude during strong contraction, and recruitment pattern during maximal voluntary contraction were recorded. The differences in EAS-EMG and US-EMG results between MSA-P, PD, and PSP were analyzed. In EAS-EMG examination, the average duration of MUPs of MSA-P was significantly longer than that of PD and PSP; the percentage of polyphasic MUPs and the ratio of simple phase and simple-mix phase of MSA-P and PSP were significantly higher than that of PD; the amplitude during strong contraction of MSA-P was significantly lower than that of PD. In US-EMG examination, the average duration of MUPs in male MSA-P was significantly longer than that in male PD and PSP; the ratio of simple phase and simple-mix phase in male MSA-P was significantly higher than that in male PD; there was no statistical difference in US-EMG indexes between male PD and PSP male. And because only one female PSP was examined, only female MSA-P and PD were compared, the average duration of MUPs in female MSA-P was significantly longer than that in female PD; the ratio of simple phase and simple-mix phase in female MSA-P was significantly higher than that in female PD. The average duration of MUPs and the ratio of the simple phase and simple-mix phase of EAS-EMG and US-EMG all can provide the basis for the differential diagnosis between MSA-P and PD. US-EMG can be used as a supplement to differentiate MSA-P from PD when EAS-EMG is limited. The only discriminating indicator between MSA-P and PSP seems to be the average duration of MUPs of EAS-EMG and US-EMG. There is still a lack of diagnostic electromyography indicators between PD and PSP.

External anal sphincter electromyography in multiple system atrophy: implications for diagnosis, clinical correlations, and novel insights into prognosis.

Multiple system atrophy is a sporadic, progressive, adult-onset, neurodegenerative disorder characterized by autonomic dysfunction symptoms, parkinsonian features, and cerebellar signs in various combinations. An early diagnosis of multiple system atrophy is of utmost importance for the proper prevention and management of its potentially fatal complications leading to the poor prognosis of these patients. The current diagnostic criteria incorporate several clinical red flags and magnetic resonance imaging markers supporting diagnosis of multiple system atrophy. Nonetheless, especially in the early disease stage, it can be challenging to differentiate multiple system atrophy from mimic disorders, in particular Parkinson's disease. Electromyography of the external anal sphincter represents a useful neurophysiological tool for differential diagnosis since it can provide indirect evidence of Onuf's nucleus degeneration, which is a pathological hallmark of multiple system atrophy. However, the diagnostic value of external anal sphincter electromyography has been a matter of debate for three decades due to controversial reports in the literature. In this review, after a brief overview of the electrophysiological methodology, we first aimed to critically analyze the available knowledge on the diagnostic role of external anal sphincter electromyography. We discussed the conflicting evidence on the clinical correlations of neurogenic abnormalities found at external anal sphincter electromyography. Finally, we reported recent prognostic findings of a novel classification of electromyography patterns of the external anal sphincter that could pave the way toward the implementation of this neurophysiological technique for survival prediction in patients with multiple system atrophy.

Diagnostic and Prognostic Value of External Anal Sphincter EMG Patterns in Multiple System Atrophy.

ABSTRACTBackgroundIt is debated whether external anal sphincter (EAS) electromyography can distinguish between multiple system atrophy (MSA) and Parkinson's disease (PD), whereas its usefulness for MSA prognosis is unknown.ObjectivesWe explored the diagnostic and prognostic value and clinical correlations of EAS electromyography patterns in MSA.MethodsWe collected clinical data and EAS electromyography findings in 72 patients with MSA and 21 with PD.ResultsWe identified four EAS patterns. The normal pattern was frequently observed in PD and associated with prolonged survival when identified in MSA. Abnormal patterns were predominant in MSA. The most severe pattern was associated with the highest likelihood of MSA diagnosis and with the worst prognosis in the MSA cohort. MSA patients with EAS abnormalities often showed urogenital symptoms and fecal incontinence.ConclusionsThe increasing severity of EAS electromyography patterns paralleled diagnostic accuracy and survival in MSA, and correlated with prevalence of bladder and bowel symptoms. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Relation between pelvic floor neurophysiological abnormalities and erectile dysfunction in patients with obstructed defecation

BackgroundObstructed defecation is a common pelvic floor medical problem among adult population. Pelvic floor disorders were reported to be associated with sexual dysfunction including erectile dysfunction among male patients. The aim was to determine the relation between pelvic floor neurophysiological abnormalities and erectile dysfunction in male patients with obstructed defecation.MethodsThis cross-sectional study included 65 married male patients with obstructed defecation and a control group consisted of 15 apparently healthy married males. Assessment of obstructed defecation severity was done by using modified obstructed defecation score, time of toileting and Patient Assessment of Constipation-Quality of Life questionnaire. Assessment of erectile functions was done using erectile function domain of International Index of Erectile Function questionnaire and Erectile Dysfunction-Effect on Quality of Life Questionnaire. Anal manometry and dynamic pelvis magnetic resonance imaging were done. Electrophysiological studies included pudendal nerve motor conduction study and needle electromyography of external anal sphincter, puborectalis and bulbocavernosus muscles.ResultsThere were 32 patients (49.2%) who had erectile dysfunction. The maximum straining anal pressure was significantly higher among patients with erectile dysfunction. Pudendal nerve terminal motor latency was significantly delayed and the percentage of bilateral pudendal neuropathy was significantly higher among patients with erectile dysfunction. The percentage of electromyography evidence of denervation with chronic reinnervation in the external anal sphincter and bulbocavernosus muscles were significantly higher among patients with erectile dysfunction. Regression analysis detected three co-variables to be associated with significantly increasing the likelihood of development of erectile dysfunction. These were maximum straining anal pressure (odd ratio = 1.122), right pudendal nerve terminal motor latency (odd ratio = 3.755) and left pudendal nerve terminal motor latency (odd ratio = 3.770).ConclusionsErectile dysfunction is prevalent among patients with obstructed defecation. It is associated with characteristic pelvic floor electrophysiological abnormalities. Pelvic floor neurophysiological changes vary from minimal to severe neuromuscular abnormalities that usually accompanying erectile dysfunction. Pudendal neuropathy and increased maximum straining anal pressure are essential risk factors for increasing the likelihood of development of erectile dysfunction in patients with obstructed defecation.

Bladder and bowel responses to lumbosacral epidural stimulation in uninjured and transected anesthetized rats

Spinal cord epidural stimulation (scES) mapping at L5-S1 was performed to identify parameters for bladder and bowel inhibition and/or contraction. Using spinally intact and chronic transected rats of both sexes in acute urethane-anesthetized terminal preparations, scES was systematically applied using a modified Specify 5–6–5 (Medtronic) electrode during bladder filling/emptying cycles while recording bladder and colorectal pressures and external urethral and anal sphincter electromyography activity. The results indicate frequency-dependent effects on void volume, micturition, bowel peristalsis, and sphincter activity just above visualized movement threshold intensities that differed depending upon neurological intactness, with some sex-dependent differences. Thereafter, a custom-designed miniature 15-electrode array designed for greater selectivity was tested and exhibited the same frequency-dependent urinary effects over a much smaller surface area without any concurrent movements. Thus, select activation of autonomic nervous system circuitries with scES is a promising neuromodulation approach for expedient translation to individuals with SCI and potentially other neurologic disorders.

Sphincter muscle activity before and after delivery: Does it depend on the type of birth?

There are ongoing discussions whether cesarean section is the safest mode of childbirth to prevent pelvic floor disorders. Pelvic floor electromyography (EMG) allows the analysis of external anal sphincter (EAS) function during voluntary contractions. The primary objective of this study was the evaluation of EMG amplitude of external anal sphincter in women who had vaginal delivery, compared to women who had cesarean section. The secondary objective was to evaluate the anal incontinence score changes before and after delivery between the groups, and to look for any relationship between the clinical and EMG findings. Multichannel surface EMG was detected during maximal contractions in three sessions: (i) during pregnancy, (ii) 6 weeks after delivery and (iii) 1 year after delivery. Women were divided into two groups: cesarean section and vaginal delivery. External anal sphincter EMG amplitude decreases 6 weeks after vaginal deliveries from 10.1 to 8.6 μV with effect size of 0.4, but returns to baseline after 1 year. No differences were observed between groups in all other variables. No differences were observed after 1 year in EMG activity between the two groups; however, a slight decrease of sphincter muscle amplitude was noted 6 weeks after vaginal delivery. The delivery mode does not have effect on the EAS amplitude 1 year after delivery. Incontinence score slightly increased in both groups after delivery, with no significant differences between the two groups. No association was observed between the increase of incontinence score and the decrease of EMG signal amplitude.

Differential Diagnosis of Multiple System Atrophy-Parkinsonism and Parkinson's Disease Using α-Synuclein and External Anal Sphincter Electromyography.

Background and aim: Discriminating multiple system atrophy-parkinsonism (MSA-P) from Parkinson's disease (PD) is challenging. We aimed to provide a new method to make an identification between MSA-P and PD by combining biofluid marker with electrophysiology marker.Methods: The XYCQ EV Enrichment KIT was applied to extract extracellular vesicles (EVs) from saliva. The levels of α-syn which included total α-syn (α- synTotal), phosphorylated-ser129 α-syn (α-synPS129) and oligomeric α-syn (α-synOlig) in EVs of saliva were tested by new developed Electrochemiluminescence (ECL) assays. We collected multi-motor unit potential (MUP) of all participants who conducted external anal sphincter electromyography (EAS-EMG). The duration, phase, amplitude and satellite potential of EAS-EMG were analyzed. The Receiver operator characteristic (ROC) curve was adopted to analyze the diagnostic utility of α-syn in EVs of saliva, EAS-EMG for MSA-P.Results: In EVs of saliva, the α-synTotal concentrations were lower in MSA-P than PD (P = 0.003). No significant difference was shown in α-synOlig and α-synPS129. α-synTotal 4.46 pg/ng distinguished MSA-P from PD with area under the curve (AUC) 0.804. Compared with PD, the duration, phase and satellite potential of EAS-EMG in MSA-P were increased (P = 0.002, 0.008, 0.001). There was no significant difference in amplitude. ROC curve showed that the duration (AUC: 0.780), phase (AUC: 0.751), and satellite potential (AUC: 0.809) had both diagnostic value for MSA-P. The combination of α-synTotal in salivary EVs and EAS-EMG (including duration, phase and satellite potential) could efficiently make a differentiation between MSA-P and PD with sensitivity of 100% and specificity of 86%. The AUC value was 0.901.Conclusion: The study suggested the combination of α-synTotal in salivary EVs and EAS-EMG could help efficiently distinguish MSA-P from PD.

Differential value of external anal- and urethral-sphincter electromyography in multiple system atrophy cerebellar type and spinocerebellar ataxias

ObjectiveClinically differentiating multiple system atrophy cerebellar type (MSA-C) and spinocerebellar ataxias (SCAs) is challenging, especially at early disease stages, because of their similarities in clinical manifestation and imaging results. The purpose of this study was to explore the value of external anal-sphincter electromyography (EAS-EMG) and urethral-sphincter electromyography (US-EMG) for distinguishing between MSA-C and SCAs. MethodsA total of 51 subjects, including 33 MSA-C and 18 SCAs, were recruited. Average duration and amplitude of motor unit potentials (MUPs), percentage of polyphasic MUPs, amplitude during strong contraction and recruitment pattern during maximal voluntary contraction were recorded and analyzed to identify differential diagnostic results of EAS-EMG and US-EMG for MSA-C and SCAs. ResultsSignificant differences in average MUP duration, percentage of polyphasic MUPs, and ratio of simple phase and simple-mix phase using EAS-EMG were noted between patients with MSA-C and SCAs. These same parameters also differed significantly between MSA-C and SCAs male patients using US-EMG. ConclusionsEAS-EMG may serve as a potential method for early differential diagnosis between patients with MSA-C and SCAs. Furthermore, US-EMG could be a supplementary method for males when EAS-EMG is not available.

Investigation of Bowel Function with Anorectal Manometry in a Rat Spinal Cord Contusion Model.

Bowel dysfunction after chronic spinal cord injury (SCI) is a common source of morbidity and rehospitalization. Typical complications include constipation, fecal impaction, incontinence, abdominal distention, autonomic dysreflexia, and the necessity of interventions (i.e., suppositories, digital stimulation) to defecate. Numerous surveys have confirmed that the remediation of bowel complications is more highly valued for quality of life than improvements in walking. Much of what is known about bowel function after SCI for diagnosis and research in humans has been gained using anorectal manometry (ARM) procedures. However, ARM has been underutilized in pre-clinical animal work. Therefore, a novel combination of outcome measures was examined in the current study that incorporates functional output of the bowel (weekly fecal measurements), weight gain (pre-injury to terminal weight), and terminal ARM measurement with external anal sphincter electromyography under urethane anesthesia. The results indicate higher fecal output after contusion during the sub-acute period (4-7 days) post-injury, changes in the composition of the feces, and functionally obstructive responses in a specific section of the rectum (increased baseline pressure, increased frequency of contraction, and reduced ability to trigger a giant contraction to a distension stimulus). These results demonstrate significant bowel dysfunction in the rodent SCI contusion model that is consistent with data from human research. Thus, the combined measurement protocol enables the detection of changes and can be used, with minimal cost, to assess effectiveness of therapeutic interventions on bowel complications.

Differential Diagnosis Of Multiple-System Atrophy With Parkinson's Disease By External Anal- And Urethral-Sphincter Electromyography.

BackgroundThe differential diagnosis of Parkinson’s disease (PD) with multiple-system atrophy (MSA) is difficult because of their similarity in symptoms and signs. The objective of this study was to investigate the value of external anal-sphincter electromyography (EAS-EMG) and urethral-sphincter electromyography (US-EMG) in differentiating MSA from PD.MethodsA total of 201 patients, — 101 MSA and 100 PD — were recruited in this study. Average duration and amplitude of motor unit potentials (MUPs), percentage of polyphasic MUPs, amplitude during strong contractions, and recruitment patterns during maximal voluntary contractions were recorded and analyzed to assess diagnostic efficiency of EAS-EMG and US-EMG for MSA.ResultsSignificant differences in average MUP duration and recruitment patterns during maximal voluntary contractions were found between patients with MSA and patients with PD using both EAS-EMG (P<0.001, P<0.001) and US-EMG (P<0.001, P<0.001). The percentage of polyphasic MUPs and amplitude during strong contractions showed significant differences in MSA and PD using only EAS-EMG (P<0.001, P=0.005). Cutoff points for average MUP duration in EAS-EMG and US-EMG for differential diagnosis of MSA with PD were 10.9 and 11.1 milliseconds, respectively. With average MUP duration of EAS-EMG and US-EMG being applied jointly, sensitivity and specificity in distinguishing MSA from PD were 83.2% and 71.8%, respectively.ConclusionEAS-EMG and US-EMG were sensitive and specific methods for the diagnosis and differential diagnosis of MSA, and the combination of both would improve the diagnostic rate of MSA compared to only one method being used.

Diagnostic significance of urethral sphincter electromyography and external anal sphincter electro-myography in patients with multiple system atrophy

Diagnostic significance of urethral sphincter electromyography and external anal sphincter electro-myography in patients with multiple system atrophy

Multifunctional surface probe for less invasive stimulation of sacral somatic and autonomic outflow under EMG feedback control

Abstract Invasive electric stimulation of sacral somatic and autonomic outflow is used for treatment of urinary and anorectal functional disturbances and selective monitoring of the autonomic nerve-sparing technique in pelvic surgery, the so called pelvic intraoperative neuromonitoring. The aim of this experimental study was to investigate a less invasive approach for simultaneous stimulation of sacral somatic and autonomic outflow and concomitant recording of feedback. A newly developed multifunctional surface probe for simultaneous transrectal stimulation and electromyography (EMG) of external (EAS) and internal anal sphincter (IAS) was investigated in a consecutive series of six male pigs. The probe (cathode) was designed for intra-anal/-rectal application. An additional surface anode was placed on the animals´ back at the level of the sacrum. Each animal underwent autonomic nerve-sparing low anterior rectal resection. The transrectal stimulations followed a standardized protocol. Further direct stimulation of the surgically exposed pelvic autonomic nerves was carried out with a hand-guided bipolar microfork probe. In all six experiments, the transrectal stimulation resulted in significantly increased EMG signals of the somatically innervated EAS (21.0 μV (interquartile range (IQR): 17.8; 64.4) before stimulation vs. 375.8 μV (IQR: 103.4; 895.9) during stimulation, p = 0.004) and autonomically innervated IAS (35.1 μV (IQR: 27.9; 41.7) before stimulation vs. 1115.7 μV (IQR: 420.1; 2920.3) during stimulation, p = 0.008). Subgroup analysis of the observed IAS EMG signals under transrectal stimulation and hand guided direct stimulation revealed no significant differences between both methods (70.5 μV (IQR: 31.5; 322.7) vs. 320.3 μV (IQR: 204.0; 358.0), p = 0.109). The newly developed multifunctional surface probe enabled successful transrectal stimulation of sacral somatic and autonomic outflow under EMG feedback control. The clinical value of this less invasive approach for the treatment of functional disturbances needs further investigations.

Postvoid residual predicts the diagnosis of multiple system atrophy in Parkinsonian syndrome

ObjectiveIt is difficult to differentiate multiple system atrophy (MSA) from Parkinson's disease (PD) at least in the early stage. Urodynamic study (UDS) is useful in differentiating MSA from PD. We aimed to clarify which UDS parameter was useful in differentiating MSA from PD. MethodsWe retrospectively reviewed 273 cases and performed UDS and external anal sphincter electromyography (EAS-EMG) in patients with MSA (n=182) and PD (n=91). We analyzed the utility of UDS parameters, including postvoid residuals (PVR), detrusor overactivity (DO), degree of bladder contraction, and mean duration of motor unit potentials (MUPs) in EAS-EMG, for differentiating MSA from PD. ResultsPVR>150ml during free-flow study strongly indicated MSA rather than PD (OR 8.723, 95% CI 2.612–29.130, p<0.001). ‘Weak detrusor’ also suggested MSA, but it was not a statistically significant indicator (OR 10.598, 95% CI 0.359–312.473, p=0.172). DO and neurogenic changes in EAS-EMG (mean duration of MUPs>10ms) did not significantly contribute to the differentiation of MSA from PD. ConclusionsPVR>150ml during free-flow study might be more useful than other UDS parameters in clinically differentiating MSA from PD.

Nonrelaxing Pelvic Floor Dysfunction Is an Underestimated Complication of Ileal Pouch-Anal Anastomosis.

Nonrelaxing pelvic floor dysfunction (N-RPFD), or dyssynergic defecation, is the paradoxical contraction and/or impaired relaxation of pelvic floor and anal muscles during defecation. Few studies have evaluated this disorder in patients with an ileal pouch-anal anastomosis (IPAA). We investigated the frequency of N-RPFD in patients with and without chronic pouchitis following IPAA and the effectiveness of biofeedback therapy within this population. We conducted a retrospective study of all patients with an IPAA who underwent anorectal manometry between January 2000 and March 2015 (n= 111). N-RPFD was diagnosed in patients with symptoms consistent with a pouch evacuation disorder and 1 or more of the following abnormal tests: anorectal manometry, balloon expulsion test, barium or magnetic resonance defecography, or external anal sphincter electromyography. Patients who completed biofeedback therapy were identified and assessed to determine symptomatic response. Of the 111 patients evaluated, 83 (74.8%) met criteria for N-RPFD. A significantly higher proportion of patients with chronic pouchitis were diagnosed with N-RPFD than patients without chronic pouchitis (83.3% vs 62.2%, respectively; P= .012). Most patients diagnosed with N-RPFD had abnormal results from the balloon expulsion test (78.3%); 53.0% of patients diagnosed with N-RPFD had abnormal findings from external anal sphincter electromyography, 25.3% had abnormal defecography findings, and 20.5% had abnormal findings from anorectal manometry. Twenty-two patients completed biofeedback therapy: 15 patients (68.2%) had mild-moderate improvement and 5 patients (22.7%) had significant improvement of symptoms. N-RPFD occurs in almost 75% of patients with an IPAA, especially in patients with chronic pouchitis. Biofeedback seems to be an effective therapy for patients with an IPAA and N-RPFD, but further studies are needed for validation.

ID 49 – Electrophysiological tests in diagnosis of pelvic floor disorders

Objective The aim of this study was to examine whether pelvic floor electrophysiological (PFE) tests contribute to diagnosis of pelvic floor disorders. Methods Clinical information and PFE data of 18 patients consecutively referred for assessment of possible pelvic floor disorders, were analysed retrospectively. The results of pudendal somatosensory evoked potentials (SEP), penilo/cliterocavernosus reflex, electromyography (EMG) of external anal sphincter (EAS) muscle were analysed. The clinical course of the patients and the influence of the electrophysiological results to clinicians’ decision were reviewed from patient files. Results Ten of the 18 patients had abnormal PFE tests showing pudendal neuropathy, and all 10 had delayed latencies or absent responses of the penilo/cliterocavernosus reflex. EMG of EAS was abnormal in 8 and pudendal SEP in 2 patients. For 10 patients, the electrophysiological assessment contributed to the diagnosis by confirming the referral theory of pelvic floor disorder. For the remaining patients the assessment enabled the clinician to change the diagnosis, initiate further examination, or treatment. Conclusion Pelvic floor electrophysiology may contribute to the diagnosis of pelvic floor disorders. Penilo/cliterocavernosus reflex is suggested to be a sensitive test. Key message Electrophysiological tests have an impact on the diagnosis or further course of pelvic floor disorders.