The bulbocavernosus reflex in urology: a prospective study of 299 patients

Spinal Cord Lower Urinary Tract Control in Humans

BACKGROUND AND OBJECTIVE

Although there have been significant advancements in functional magnetic resonance imaging (fMRI) studies that have enhanced our understanding of brain control over bladder function in humans, a notable gap still exists in exploring spinal cord involvement in real-time. The objective of this study was to develop and validate an fMRI protocol to assess innate spinal cord activity in humans within regions associated with bladder function.

METHODS

Twenty healthy adult participants 9 men, 11 women underwent functional magnetic resonance imaging (fMRI) of the spinal cord during implementation of a natural bladder filling protocol and simulated bulbocavernosus reflex (sBCR). Anatomical images were obtained, followed by resting-state and task-based fMRI assessments during both full and empty bladder states. Functional spinal neuroimaging data were analyzed using a custom pipeline comprised of Spinal Cord Toolbox, FSL, and MATLAB scripts for preprocessing and analysis.

KEY FINDINGS AND LIMITATIONS

Our preliminary findings revealed activation in 15 participants (7 men, 8 women), exhibiting diverse patterns of activity across the T10-S5 neuronal segments during task-fMRI sessions conducted with both empty and full bladder conditions during sBCR. The identified activated regions included sympathetic (T10-L2), parasympathetic (S2-S4), and somatic nuclei (S2-S4), previously implicated in facilitating lower urinary tract (LUT) control. Notably, our preliminary findings suggest that sex differences may influence these activation patterns, though further investigation and second-level analysis are warranted to confirm this observation.

CONCLUSIONS

Although preliminary, our findings demonstrate, for the first time, the efficacy of our fMRI protocol in detecting task-induced activity in the lumbosacral spinal cord, underscoring our capability to precisely target specific regions responsible for regulating LUT function.

Can We Improve Our Routine Urological Assessment to Exclude Neurogenic Causes for Lower Urinary Tract Dysfunction? ICI-RS 2024

AIMS

After presentation with urinary symptoms, an underlying neurological mechanism sometimes emerges subsequently. Increased awareness may bring earlier diagnosis, improving prognosis and outcomes.

METHODS

A 2024 International Consultation on Incontinence Research Society think-tank considered the clinical pathway for identification of an undiagnosed neurological or autonomic contribution precipitating urinary symptoms, and the implications for prognosis.

RESULTS

Alongside adult-onset neurogenic conditions, potential for missed diagnosis includes congenital and pediatric-acquired neurogenic conditions, which may become symptomatic during a growth spurt due to spinal cord tethering. Detailed assessment is needed, also considering bowel and sexual dysfunction, with timely referral to neurology to reduce preventable progression of disease. In neurological assessment, control of micturition is often poorly characterized compared with other aspects of spinal cord function and the cranial nerves. Screening tools may be used to identify people who have increased likelihood of particular conditions, but currently available tools are either single-system or population specific. In addition to the general pelvic examination, the assessment of sacral reflexes and pelvic sensations can suggest a neurological mechanism, though the sensitivity and specificity of the neuro-urological examination is unknown. Including the results of the neuro-perineal examination in the urodynamic report may improve the interpretation of the results and potentially support a neurological aetiology.

CONCLUSION

Future research should consider the value of neuro-urological examination in diagnosis of occult neurological disease, the development of an occult neurology screening tool/risk scoring based on pelvic organ symptoms, and appropriateness of non-neurologist practitioners requesting neurological investigations such as MRI scanning.

CLINICAL TRIAL REGISTRATION

Does not apply.

Bedside electromyography for clinical assessment of sacral motor and reflex activity adapted for patients hospitalized with acute neurological conditions: a pilot study

STUDY DESIGN

Pilot cohort study.

OBJECTIVE

To develop and implement a sacral electromyographic (sEMG) technique at bedside to ascertain sparing of sacral motor activity and reflexes in patients hospitalized for acute neurological conditions.

SETTING

Hôpital du Sacré-Coeur de Montréal a Canadian Level-1 university trauma center specialized in SCI care.

METHODS

Nine patients underwent digital rectal examination (DRE) and sEMG, assessing voluntary anal contraction and sacral spinal reflexes (bulbocavernosus reflex and the anal wink). Our sEMG technique utilized surface recording electrodes and tactile elicitation of reflexes. EMG signal was acquired at bedside through the Noraxon MR3 system.

RESULTS

It was quick, well accepted and did no harm. We found that contrary to the DRE, sEMG detected subclinical sacral motor activity and reflexes in 20% of cases for voluntary anal contraction and 40% of cases for the anal wink.

CONCLUSION

We believe our sEMG technique is a powerful tool able to enhance management of patients suffering from acute neurological impairments and requiring sacral function assessment.

Krause corpuscles are genital vibrotactile sensors for sexual behaviours

Krause corpuscles, which were discovered in the 1850s, are specialized sensory structures found within the genitalia and other mucocutaneous tissues1-4. The physiological properties and functions of Krause corpuscles have remained unclear since their discovery. Here we report the anatomical and physiological properties of Krause corpuscles of the mouse clitoris and penis and their roles in sexual behaviour. We observed a high density of Krause corpuscles in the clitoris compared with the penis. Using mouse genetic tools, we identified two distinct somatosensory neuron subtypes that innervate Krause corpuscles of both the clitoris and penis and project to a unique sensory terminal region of the spinal cord. In vivo electrophysiology and calcium imaging experiments showed that both Krause corpuscle afferent types are A-fibre rapid-adapting low-threshold mechanoreceptors, optimally tuned to dynamic, light-touch and mechanical vibrations (40-80 Hz) applied to the clitoris or penis. Functionally, selective optogenetic activation of Krause corpuscle afferent terminals evoked penile erection in male mice and vaginal contraction in female mice, while genetic ablation of Krause corpuscles impaired intromission and ejaculation of males and reduced sexual receptivity of females. Thus, Krause corpuscles of the clitoris and penis are highly sensitive mechanical vibration detectors that mediate sexually dimorphic mating behaviours.

Conception and implementation of an MRI-compatible device to elicit the bulbocavernosus reflex for an open spinal cord study

OBJECTIVE

Functional MRI (fMRI) can be employed to assess neuronal activity in the central nervous system. However, investigating the spinal cord using fMRI poses several technical difficulties. Enhancing the fMRI signal intensity in the spinal cord can improve the visualization and analysis of different neural pathways, particularly those involved in bladder function. The bulbocavernosus reflex (BCR) is an excellent method for evaluating the integrity of the sacral spinal cord. Instead of stimulating the glans penis or clitoris, the BCR can be simulated comfortably by tapping the suprapubic region. In this study, we explain the necessity and development of a device to elicit the simulated BCR (sBCR) via suprapubic tapping while conducting an fMRI scan.

METHODS

The device was successfully tested on a group of 20 healthy individuals. Two stimulation task block protocols were administered (empty vs. full bladder). Each block consisted of 40 s of suprapubic tapping followed by 40 s of rest, and the entire sequence was repeated four times.

RESULTS

Our device can reliably and consistently elicit sBCR noninvasively as demonstrated by electromyographic recording of pelvic muscles and anal winking. Participants did note mild to moderate discomfort and urge to void during the full bladder task.

CONCLUSION

Our device demonstrates an efficacious approach to elicit sBCR within an MRI bore to assess sacral spinal cord functional activity without generating any significant motion artifacts.

SIGNIFICANCE

This device can explore the mechanisms and processes controlling urinary, digestive, or sexual function within this region in humans.

Bulbocavernosus Reflex Has No Prognostic Features During the Acute Evaluation of Spinal Cord Injuries

The bulbocavernosus reflex (BCR) has been used during the initial evaluation of a spinal cord injury patient as a metric to determine prognosis and whether the patient is in "spinal shock." This reflex has been less utilized over the last decade, and therefore a review was performed to assess the value of BCR in patient prognosis. The North American Clinical Trials Network (NACTN) for Spinal Cord Injury (SCI) is a consortium of tertiary medical centers that includes a prospective SCI registry. The NACTN registry data was analyzed to evaluate the prognostic implication of the BCR during the initial evaluation of a spinal cord injury patient. SCI patients were divided into those with an intact or absent BCR during their initial evaluation. Associations of participants' descriptors and neurological status on follow-up were performed, followed by associations with the presence of a BCR. A total of 769 registry patients with recorded BCRs were included in the study. The median age was 49 years (32-61 years), and the majority were male (n = 566, 77%) and white (n = 519, 73%). Among included patients, high blood pressure was the most common comorbidity (n = 230, 31%). Cervical spinal cord injury was the most common (n = 470, 76%) with fall (n = 320, 43%) being the most frequent mechanism of injury. BCR was present in 311 patients (40.4%), while 458 (59.6%) had a negative BCR within 7 days of injury or before surgery. At 6 months post-injury, 230 patients (29.9%) followed up, of which 145 had a positive BCR, while 85 had a negative BCR. The presence/absence of BCR was significantly different in patients with cervical (p = 0.0015) or thoracic SCI (p = 0.0089), or conus medullaris syndrome (p = 0.0035), and in those who were American Spinal Injury Association Impairment Scale grade A (p = 0.0313). No significant relationship was observed between BCR results and demographics, AIS grade conversion, motor score changes (p = 0.1669), and changes in pin prick (p = 0.3795) and light touch scores (p = 0.8178). In addition, cohorts were not different in surgery decision (p = 0.7762) and injury to surgery time (p = 0.0681). In our review of the NACTN spinal cord registry, the BCR did not provide prognostic utility in the acute evaluation of spinal cord injury patients. Therefore, it should not be used as a reliable marker for predicting neurological outcomes post-injury.

Alto porcentaje de ausencia de reflejo bulbocavernoso en pacientes neurológicamente sanos con disfunción vesical

Introducción y Objetivo El reflejo bulbocavernoso (RBCV) se ha observado ausente incluso en pacientes neurológicamente sanos. Los trastornos funcionales del piso pélvico deben incluir su evaluación.

Nuestro objetivo primario fue evaluar la prevalencia de ausencia de RBCV en pacientes sanos. El objetivo secundario fue observar la afectación del RBCV en presencia de otras comorbilidades cómo enfermedad neurológica y diabetes mellitus tipo 2.

Métodos Estudio descriptivo y retrospectivo, en el que se revisaron mil expedientes clínicos de pacientes sometidos a estudio urodinámico a quienes se les realizó exploración mecánica del RBCV como parte de una exploración rutinaria. Se realizó estadística descriptiva para las variables cuantitativas y cualitativas utilizando la prueba tde Student y la de chi cuadrado, respectivamente. Se consideraron estadísticamente significativos valores de p < 0,05.

Resultados La muestra tenía una media de edad de 59,84 años (desviación estándar [DE]: ± 14,13 años), y contenía 36,19% de mujeres y 21,13% de hombres sin enfermedad neurológica y RBCV ausente. Se observó mayor ausencia de RBCV en pacientes con presencia de enfermedad neurológica en comparación con pacientes neurológicamente sanos: 21,6% versus 10,6%, respectivamente (p < 0,0001); además, se observó una ausencia importante de RBCV en presencia de diabetes mellitus en comparación con pacientes no diabéticos: 30.8% versus 18.8%, respectivamente (p < 0,0001). No se observaron diferencias al comparar grupos con respecto a disfunción vesical.

Conclusión La ausencia de RBCV no es exclusiva de una enfermedad neurológica con repercusión de síntomas del tracto urinario inferior, y la proporción de pacientes neurológicamente sanos con ausencia de RBCV no es despreciable. No se encontró una diferencia significativa en los grupos con ausencia de RBCV con respecto a disfunción vesical.

Physical Examination Is Predictive of Cauda Equina Syndrome: MRI to Rule Out Diagnosis Is Unnecessary

STUDY DESIGN

Cross-sectional cohort study.

OBJECTIVES

Cauda equina syndrome (CES) is a neurologic emergency, and delay in diagnosis can result in irreversible impairment. Our purpose was to determine the value of physical examination in diagnosis of CES in patients complaining of bladder and/or bowel complications in the emergency department.

METHODS

Adult patients at one tertiary academic medical center that endorsed bowel/bladder dysfunction, underwent a lumbar magnetic resonance imaging (MRI), and received an orthopedic spine surgery consultation from 2008 to 2017 were included. Patients consulted for trauma or tumor were excluded. A chart and imaging review was performed to collect demographic, physical examination, and treatment data. Sensitivity, specificity, and negative and positive predictive values were calculated, and fast-and-frugal decision trees (FFTs) were generated using R.

RESULTS

Of 142 eligible patients, 10 were diagnosed with CES. The sensitivity and specificity of the exam findings were highest for bulbocavernosus reflex (BCR) (100% and 100%), followed by rectal tone (80% and 86%), postvoid residual bladder (80% and 59%), and perianal sensation (60% and 68%). The positive predictive value was high for BCR (100%), but low for other findings (13% to 31%). However, negative predictive values were consistently high for all examinations (96% to 100%). Two FFTs utilizing combinations of voluntary rectal tone, perianal sensation, and BCR resulted in no false negatives.

CONCLUSIONS

A combination of physical examination findings of lower sacral function is an effective means of ruling out CES and, with further study, may eliminate the need for MRI in many patients reporting back pain and bowel or bladder dysfunction.

What is the clinical meaning of a negative bulbocavernosus reflex in spinal cord injury patients?

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

To highlight some issues about the clinical meaning of a negative bulbocavernosus reflex (BCR) in spinal cord injury (SCI) patients.

SETTINGS

Research group University Antwerp Belgium.

METHODS

The study included 170 patients in whom the BCR was examined at a mean of 7 years post SCI. Changes over time were explored in a subset of patients.

RESULTS

BCR was negative in 45%. There was no influence of age and gender, nor could a relation be found with the American Spinal Injury Association Impairment Scale score. The anal sphincter reflex (ASR) was positive in 13% of patients with negative BCR. With a mean interval of 45 weeks, BCR changed in 32% of a subset of 44 patients (14 became positive, 3 negative), while the neurological condition did not change and no treatments had been given that could influence the outcome. The data show that a negative BCR may not only be due to a disrupted reflex nervous pathway (which in some patients is different from that of ASR), but may also be caused by a difficulty to provoke the reflex.

CONCLUSION

A negative BCR test indicates interruption of the reflex neurologic pathways, but can also depend on the ease to elicit the reflex. By also doing ASR, this dilemma can be partly solved.

The Contrasting Evidence Concerning the Effect of Male Circumcision on Sexual Function, Sensation, and Pleasure: A Systematic Review

INTRODUCTION

Active debate concerns whether male circumcision (MC) affects sexual function, penile sensation, or sexual pleasure.

AIM

To perform a systematic review examining the effect of MC on these parameters.

METHODS

PRISMA-compliant searches of PubMed, EMBASE, the Cochrane Library, and Google Scholar were performed, with "circumcision" used together with appropriate search terms. Articles meeting the inclusion criteria were rated for quality by the Scottish Intercollegiate Guidelines Network system.

MAIN OUTCOME MEASURE

Evidence rated by quality.

RESULTS

Searches identified 46 publications containing original data, as well as 4 systematic reviews (2 with meta-analyses), plus 29 critiques of various studies and 15 author replies, which together comprised a total of 94 publications. There was overall consistency in conclusions arising from high- and moderate-quality survey data in randomized clinical trials, systematic reviews and meta-analyses, physiological studies, large longitudinal studies, and cohort studies in diverse populations. Those studies found MC has no or minimal adverse effect on sexual function, sensation, or pleasure, with some finding improvements. A consensus from physiological and histological studies was that the glans and underside of the shaft, not the foreskin, are involved in neurological pathways mediating erogenous sensation. In contrast to the higher quality evidence, data supporting adverse effects of MC on function, sensation, or pleasure were found to be of low quality, as explained in critiques of those studies.

CONCLUSION

The consensus of the highest quality literature is that MC has minimal or no adverse effect, and in some studies, it has benefits on sexual functions, sensation, satisfaction, and pleasure for males circumcised neonatally or in adulthood. Morris BJ, Krieger JN. The Contrasting Evidence Concerning the Effect of Male Circumcision on Sexual Function, Sensation, and Pleasure: A Systematic Review. Sex Med 2020;8:577-598.

Lumbosacral ventral root avulsion alters reflex activation of bladder, urethra, and perineal muscles during micturition in female rabbits

AIM

To determine the effect of the lumbosacral ventral root avulsion (VRA) on the reflex activation of bladder, urethra, and activation of perineal muscles during micturition in female rabbits.

METHODS

We allocated 14 virgin female rabbits to evaluate, first, the gross anatomy of lumbosacral spinal cord root (n = 5) and, second, to determine the effect of VRA on perineal muscles during micturition (n = 9). We recorded cystometrograms, urethral pressure, and electromyograms of the bulbospongiosus (Bsm) and ischiocavernosus (Ism) muscles before and after the L6-S2 VRA. Standard variables were measured from each recording and analyzed to identify significant differences (P < .05).

RESULTS

We found that the L6-S2 VRA affected directly the bladder and urethral function and reduced the duration and the frequency of the bursting of Ism and Bsm muscles during voiding. The Ism and Bsm showed a phasic activation, of different frequencies, during the voiding phase and the L6-S2 VRA inhibited the co-contraction of the Ism and Bsm-bladder-urethra.

CONCLUSIONS

The Ism and Bsm are activated at different frequencies to trigger the voiding phase. The L6-S2 VRA affected the activity pattern of both perineal muscles. These modifications affected the bladder and urethra function. It is possible that the restoration of the activation frequency of perineal muscles contributed for an efficient bladder contraction.

The sacral exam-what is needed to best care for our patients?

Sacral reflexes are important to allow the SCI practitioner to gain information about the state of the sacral spinal cord segments. The presence of the bulbocavernosus and/or the anal wink reflex indicate an intact spinal reflex arc and reflex conal autonomic function (as part of the upper motor neuron syndrome); their absence defines a lower motor neuron syndrome. The assessment of sacral reflexes helps predict the type of bladder, bowel and sexual functions and the related therapeutic interventions. We suggest adding the sacral component of the International Standards for the Assessment of Autonomic Function after SCI (ISAFSCI) to the International Standards for the Neurologic Classification of Spinal Cord Injury (ISNCSCI) examination so there can be a detailed description of these important functions. As an alternative, the performance of sacral reflexes should be routinely required as part of the neurologic examination after SCI. Whether the sacral motor neuron system is classified as upper or lower motor neuron injury is also quite useful and as such should be present in the ISCNSCI.

Anal reflex versus bulbocavernosus reflex in evaluation of patients with spinal cord injury

The examination of sacral reflexes provides an important method to differentiate an upper motor neuron vs lower motor neuron spinal cord injury (SCI). Two common sacral mediated reflexes used as part of the neurological assessment include the bulbocavernosus reflex (BCR) and anal reflex. As the clinical information from these tests are similar, we suggest that the anal reflex provides a better first option as a non-invasive clinical assessment of sacral reflex status in clinical practice in SCI as the testing for the anal reflex is less intrusive and already being performed as part of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) by pinprick stimulation of the S4-5 dermatome.

Neurophysiology of the pelvic floor in clinical practice: a systematic literature review

Neurophysiological testing of the pelvic floor is recognized as an essential tool to identify pathophysiological mechanisms of pelvic floor disorders, support clinical diagnosis, and aid in therapeutic decisions. Nevertheless, the diagnostic value of these tests in specific neurological diseases of the pelvic floor is not completely clarified. Seeking to fill this gap, the members of the Neurophysiology of the Pelvic Floor Study Group of the Italian Clinical Neurophysiology Society performed a systematic review of the literature to gather available evidence for and against the utility of neurophysiological tests. Our findings confirm the utility of some tests in specific clinical conditions [e.g. concentric needle electromyography, evaluation of sacral reflexes and of pudendal somatosensory evoked potentials (pSEPs) in cauda equina and conus medullaris lesions, and evaluation of pSEPs and perineal sympathetic skin response in spinal cord lesions], and support their use in clinical practice. Other tests, particularly those not currently supported by high-level evidence, when employed in individual patients, should be evaluated in the overall clinical context, or otherwise used for research purposes.

The importance of the bulbocavernosus reflex

The BCR consists of the contraction of the bulbocavernosus muscle in response to squeezing the glans penis or clitoris, and is mediated through the pudendal nerve. In case of a complete lesion, the presence of BCR is indicative of intact S2-S4 spinal reflex arcs and loss of supraspinal inhibition, determining an upper motor neuron (UMN) lesion, its absence a lower motor neuron (LMN) lesion. The BCR further helps distinguish conus medullaris from cauda equina syndromes. Sensory or motor function in the most caudal sacral segments, not BCR, defines the sacral sparing as part of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). Sphincter dysfunctions are addressed in the International Standards for the Assessment of Autonomic Function after SCI (ISAFSCI). However, the ISAFSCI does not include the BCR, and is not part of the ISNCSCI. Yet, determination of the type of lesion, UMN or LMN, is very useful for the clinicians, and has important prognostic and therapeutic implications for bowel, bladder, and sexual function: UMN lesions are associated with detrusor and rectum hyperactivity, reflex erection and ejaculation, while the opposite is seen in patients with LMN lesions. BCR is complementary to the voluntary contraction of the external anal sphincter and should be added to ISNCSCI and ISAFSCI classifications, which should ultimately benefit patient care and research activities.

The value of the bulbocavernosus reflex and pudendal nerve somatosensory evoked potentials in distinguishing between multiple system atrophy and Parkinson's disease at an early stage

OBJECTIVES

This study was designed to investigate the clinical value of the bulbocavernosus reflex (BCR) and pudendal nerve somatosensory evoked potentials (PSEPs) in the differential diagnosis between multiple system atrophy (MSA) and Parkinson's disease (PD) in early stage.

MATERIALS AND METHODS

A total of 31 patients with MSA, 45 patients with PD, and 60 healthy participants were included in this study. A Keypoint EMG/EP system was used for BCR and PSEP measurements. Electrophysiological parameters were collected for statistical analysis.

RESULTS

The BCR elicitation rates were significantly lower in the patients with MSA than in the patients with PD (P<.05). Prolonged BCR latencies were found in the MSA group compared to the PD and control groups (P<.05). Bulbocavernosus reflex latencies were significantly prolonged in patients with MSA compared with PD patients showing early urogenital symptoms (P<.05). There was no significant difference in PSEP P41 latencies among the three groups (P=.434 in males, P=.948 in females). Both BCR and PSEP amplitudes were significantly lower in the MSA/PD group than in the control group (P<.001).

CONCLUSIONS

Pudendal nerve damage is more severe in MSA than in PD. Prolonged BCR latency may be valuable for distinguishing between MSA and PD in the early stages. BCR and PSEP testing may also contribute to localized and qualitative diagnosis of the distribution of neurodegenerative pathologies in these two disorders.

The management of neurogenic lower urinary tract dysfunction after spinal cord injury

The management of patients with neurogenic bladder has changed substantially over the past decades. Obtaining balanced lower urinary tract function has become possible in most patients, although, urological complications remain among the most serious complications these patients are likely to have and, even today, these can have a negative effect on quality of life. To this extent, patients with spinal cord injury (SCI) are likely to develop neurogenic bladder, and data are available on most aspects of neurogenic bladder in these patients. Data on physiology and pathophysiology form the basis of our understanding of patients' symptoms, and also provide a basis for the management of these patients. The use of conservative, and/or more invasive treatment measures, their complications and measures to prevent these complications, are all important clinical aspects that merit discussion. Considerable progress has been made in the urological management of patients with SCI over the past decades, but opportunities remain to make diagnosis more accurate and therapy more successful.

Bladder Dysfunction in Multiple Sclerosis

Multiple sclerosis (MS) involves focal neural demyelmation with relative sparing of axons and resultant impaired nerve conduction. Demyelination commonly affects the posterolateral columns of the spinal cord, with the majority of patients having cervi cal cord involvement. Forty percent of patients have lumbar cord involvement and 18 percent have sacral cord involvement. The cerebral cortex and midbram may also be affected. Lesions in any of these areas can affect voiding function.

Altered bulbocavernosus reflex in patients with multiple system atrophy

OBJECTIVES

Multiple system atrophy (MSA) is characterized by a combination of symptoms including autonomic dysfunction, parkinsonism, cerebellar ataxia, and cortico-spinal disorders. The disease can have either predominant parkinsonism or cerebellar features (MSA-P and MSA-C, respectively). The measurement of the bulbocavernosus reflex (BCR) and pudendal nerve somatosensory-evoked potentials (PSEPs) was originally developed to diagnose diabetic cystopathy and other neuropathologic diseases that share similar symptoms with MSA. We investigated the relationship between abnormalities of neurophysiological parameters and MSA, and estimated the potential value of BCR.

METHODS

Fifty-one MSA patients (28 and 23 MSA-P and 23 MSA-C patients, respectively) and 30 healthy controls who were seen at the Department of Neurology were included in the study. A Keypoint EMG/EP system was used to test BCR and PSEPs, and the latencies and amplitudes were recorded for statistical analyses.

RESULTS

The BCR was elicited in 78.4% patients with MSA (22/28 MSA-P, 18/23 MSA-C). Prolonged BCR latencies were found in patients with MSA compared with healthy controls (p < 0.001). BCR amplitudes were significantly lower in the MSA group than the control group (p < 0.001). PSEP P41 amplitudes were not significantly different between the MSA and control groups in males (p = 0.608) or females (p = 0.897). There were no significant differences in PSEP latencies among the MSA-P, MSA-C, and control groups (p = 1.0, p = 0.263, and p = 0.060, respectively).

DISCUSSION

MSA patients exhibit prolonged BCR latencies and lower amplitudes, which provides a rough anatomical localization of nervous system lesions in MSA patients.

Intraoperative recording of the bulbocavernosus reflex

: The bulbocavernosus reflex (BCR) is mediated by the sacral somatic afferent/efferent periphery as well as the sacral cord. Unfortunately, the reflex has suffered from a partly deserved reputation as difficult to implement. However, recent stratagems have improved the test's reliability. Multipulse stimulation (enhanced by double trains as required) and exacting recording technique can yield positive and remarkably reproducible results in patients of all ages and either sex. In this review, we document a 94% baseline BCR acquisition rate among 100 consecutive cases in one institution. Acceptance and routine use of the BCR is needed to help assure optimal post-operative low sacral function in intradural and extradural surgeries at the level of conus medullaris, cauda equina, sacral plexus, and the pudendal nerve. Case studies within this review illustrate the power of the BCR to predict patient outcome or, much more importantly, reverse incipient patient injury in real time.

Does male circumcision affect sexual function, sensitivity, or satisfaction?--a systematic review

INTRODUCTION

Circumcision of males is commonly carried out worldwide for reasons of health, medical need, esthetics, tradition, or religion. Whether circumcision impairs or improves male sexual function or pleasure is controversial.

AIMS

The study aims to conduct a systematic review of the scientific literature.

METHODS

A systematic review of published articles retrieved using keyword searches of the PubMed, EMBASE, and Cochrane databases was performed.

MAIN OUTCOME MEASURES

The main outcome measure is the assessment of findings in publications reporting original data relevant to the search terms and rating of quality of each study based on established criteria.

RESULTS

Searches identified 2,675 publications describing the effects of male circumcision on aspects of male sexual function, sensitivity, sensation, or satisfaction. Of these, 36 met our inclusion criteria of containing original data. Those studies reported a total of 40,473 men, including 19,542 uncircumcised and 20,931 circumcised. Rated by the Scottish Intercollegiate Guidelines Network grading system, 2 were 1++ (high quality randomized controlled trials) and 34 were case-control or cohort studies (11 high quality: 2++; 10 well-conducted: 2+; 13 low quality: 2-). The 1++, 2++, and 2+ studies uniformly found that circumcision had no overall adverse effect on penile sensitivity, sexual arousal, sexual sensation, erectile function, premature ejaculation, ejaculatory latency, orgasm difficulties, sexual satisfaction, pleasure, or pain during penetration. Support for these conclusions was provided by a meta-analysis. Impairment in one or more parameters was reported in 10 of the 13 studies rated as 2-. These lower-quality studies contained flaws in study design (11), selection of cases and/or controls (5), statistical analysis (4), and/or data interpretation (6); five had multiple problems.

CONCLUSION

The highest-quality studies suggest that medical male circumcision has no adverse effect on sexual function, sensitivity, sexual sensation, or satisfaction.

Use of the Bulbocavernosus Reflex System in assessing voiding dysfunction

PURPOSE

The Bulbocavernosus Reflex System (BRS) (Laborie, Canada) is an office-based procedure used to measure the bulbocavernosus reflex (BCR) latency period. The aim of this study is to evaluate the BCR as a predictor of specific voiding dysfunction patterns confirmed by urodynamics (UDS).

METHODS

A total of 87 men were evaluated with BRS, UDS, and electromyography at Weill Cornell Medical College from March to August 2010. Baseline characteristics, demographics, UDS, and latency parameters were recorded. Multivariate logistic regression analysis was performed to evaluate prolonged BCR (latency >45 ms) as a predictor of specific voiding dysfunction patterns.

RESULTS

The median age of men was 70.4 years (IQR 57.6-75.6). Based on UDS, 60 men were given a primary or secondary diagnosis of bladder outlet obstruction (BOO), 43 a diagnosis of detrusor overactivity (DO), 11 a diagnosis of intrinsic sphincter deficiency (ISD), and 4 a diagnosis of detrusor sphincter dyssynergia (DSD). Median BCR latency was 57.0 ms (IQR 47.5-76.5) and 68 (78%) men demonstrated a prolonged latency. In multivariate analysis, latency period was not significantly associated with DO, BOO, ISD, or DSD (p = 0.067, 0.696, 0.999, 0.971, respectively).

CONCLUSIONS

Prolonged bulbocavernosus reflex latency was not associated with DO, BOO, ISD, or DSD. Although evidence in the literature suggests a link between this reflex arc and voiding, its specific diagnostic role remains unclear. Large prospective trials are needed to further explore the role of BCR in the evaluation of patients with voiding dysfunction.

Somatic genital reflexes in rats with a nod to humans: anatomy, physiology, and the role of the social neuropeptides

Somatic genital reflexes such as ejaculation and vaginocervical contractions are produced through the striated muscles associated with the genitalia. The coordination of these reflexes is surprisingly complex and involves a number of lumbosacral spinal and supraspinal systems. The rat model has been proven to be an excellent source of information regarding these mechanisms, and many parallels to research in humans can be drawn. An understanding of the spinal systems involving the lumbosacral spinal cord, both efferent and afferent, has been generated through decades of research. Spinal and supraspinal mechanisms of descending excitation, through a spinal ejaculation generator in the lumbar spinal cord and thalamus, and descending inhibition, through the ventrolateral medulla, have been identified and characterized both anatomically and physiologically. In addition, delineation of the neural circuits whereby ascending genitosensory information regarding the regulation of somatic genital reflexes is relayed supraspinally has also been the topic of recent investigation. Lastly, the importance of the "social neuropeptides" oxytocin and vasopressin in the regulation of somatic genital reflexes, and associated sociosexual behaviors, is emerging. This work not only has implications for understanding how nervous systems generate sexual behavior but also provides treatment targets for sexual dysfunction in people.

Sacral neurophysiologic study in patients with chronic spinal cord injury

AIMS

Neurophysiologic testing of the sacral reflex has demonstrated utility in the diagnosis of sacral lower motor neuron lesions. The aim of the present study was to also apply this test to patients with upper motor neuron lesions.

METHODS

A group of 16 male patients with chronic suprasacral spinal cord lesions was prospectively recruited. In addition to history and clinical neurologic examination (including anal sphincter tone, saddle sensation, and penilo-cavernosus reflex testing), sacral neurophysiologic studies were performed. Neurophysiologic testing included quantitative electromyography of the external anal sphincter (motor unit potential (MUP) count during relaxation and MUP analysis), and neurophysiologic measurement of the penilo-cavernosus reflex (elicitation threshold and latency) on electrical stimulation. The findings were compared to data obtained in the control group of 26 men.

RESULTS

Clinical elicitability of the penilo-cavernosus reflex was increased, and the neurophysiologically measured reflex threshold reduced in patients (<0.02). No significant differences were found in clinical assessment of anal sphincter tone, MUP count, reflex latency, and quantitative MUP analysis. The diagnostic sensitivity of individual parameters was low (≤25%).

CONCLUSIONS

In patients with chronic spinal cord injury, increased elicitability of the penilo-cavernosus reflex was found. However, none of the assessed neurophysiologic parameters was found to assist in the diagnosis of the sacral upper motor neuron lesion in individual patients. The shortened sacral reflex latency found in individual patients is therefore not a consequence of a suprasegmental lesion, but rather of the low position of the conus medullaris (e.g., in tethered cord syndrome).

Clinical approach and office evaluation of the patient with pelvic floor dysfunction

Pelvic floor disorders are common health issues for women and have a great impact on quality of life. These disorders can present with a wide spectrum of symptoms and anatomic defects. This article reviews the clinical approach and office evaluation of patients with pelvic floor disorders, including pelvic organ prolapse, urinary dysfunction, anal incontinence, sexual dysfunction, and pelvic pain. The goal of treatment is to provide as much symptom relief as possible. After education and counseling, patients may be candidates for non-surgical or surgical treatment, and expectant management.

The neurourological examination in women

The review provides a description of a physical examination protocol to rule out significant neurologic disease as a cause for a woman's sexual complaints, or to confirm a neurologic cause for the sexual dysfunction, particularly in women with known neurologic disease.

Neurophysiology in neurourology

The bladder has only two essential functions. It stores and periodically empties liquid waste. Yet it is unique as a visceral organ, allowing integrated volitional and autonomous control of continence and voiding. Normal function tests the integrity of the nervous system at all levels, extending from the neuroepithelium of the bladder wall to the frontal cortex of the brain. Thus, dysfunction is common with impairment of either the central or peripheral nervous system. This monograph presents an overview of the neural control of the bladder as it is currently understood. A description of pertinent peripheral anatomy and neuroanatomy is provided, followed by an explanation of common neurophysiological tests of the lower urinary tract and associated structures, including both urodynamic and electrodiagnostic approaches. Clinical applications are included to illustrate the impact of nervous system dysfunction on the bladder and to provide indications for testing.

The penilo-cavernosus reflex: Comparison of different stimulation techniques

AIMS

Although several stimulation techniques are available to elicit sacral reflexes, no comparative data on their utility has been published. The aim of the present study was to determine the most sensitive stimulation technique used for neurophysiologic recording of the penilo-cavernosus reflex.

METHODS

Neurophysiologic measurement of the penilo-cavernosus reflex on single and double pulse electrical, and on mechanical stimulation was performed in 52 men with chronic cauda equina or conus medullaris lesions. Responses were recorded by a standard concentric EMG needle electrode inserted consecutively into the left and right bulbocavernosus muscle. Responses were regarded as abnormal when non-elicitable, of increased latency, or of increased latency compared to the contralateral side, using my previously published normative ranges. Sensitivity was calculated separately for each side using all three stimulation techniques.

RESULTS

Sensitivities of the electrophysiological measurement of the penilo-cavernosus reflex on single electrical, double electrical, and mechanical stimulation were 70%, 73%, and 73%, respectively. The combined use of all three stimulation modalities increased the sensitivity to 82%. The use of interside latency differences did not increase the sensitivity using any of the stimulation modalities.

CONCLUSIONS

No significant differences in sensitivity were found between the three stimulation techniques, and only a very modest increase was found on concomitant application of all three. Because of the high elicitability of responses, the lower stimulation strength required, and the opportunity to measure sensory and reflex thresholds, the authors' preference is to use double pulse electrical stimulation.

Surgery Insight: surgical management of postprostatectomy incontinence--the artificial urinary sphincter and male sling

Stress urinary incontinence in men is usually a result of intrinsic sphincter deficiency following prostate cancer surgery. Active conservative management with fluid restriction, medication management and pelvic floor exercises is indicated for the first 12 months. If bothersome incontinence persists, urodynamic evaluation is indicated in order to assess detrusor storage function, contractility and sphincteric integrity. Standard surgical options include urethral bulking agents, artificial urinary sphincter (AUS) and male sling. Periurethral injection of bulking agents is satisfactory in only a minority of patients, leaving AUS and male sling as the most common surgical treatments. In patients with severe urinary incontinence, AUS seems to have a higher rate of success than the male sling. Furthermore, AUS is indicated in men with detrusor hypocontractility as adequate detrusor contractility is needed to overcome the fixed resistance of the sling. In patients with milder levels of stress incontinence, the two techniques have approximately equal efficacy in the short-to-intermediate term. While current reports of the male sling are generally limited to 1-4 years' follow-up, the infection, erosion, and revision rate for the male sling seem somewhat lower than that for the AUS in appropriately chosen patients.

Intraoperative mapping of sacral nervous system (S2-4)

Electrophysiological mapping of the sacral nervous system was used during operations on 80 patients with conus and cauda equina lesions. At surgery, under controlled muscle relaxation, the sacral neural elements (S2-4) were mapped using direct mono-polar stimulation and recording of compound muscle action potentials (CMAPs) from the external anal sphincter (EAS). Responses were obtained in 86.25% (69/80) of the patients. In 33 (82.5%) out of 40 patients with preoperative deficits involving the S2-4 segments, CMAPs could be elicited. Identification of nerve roots was useful in dissection of lipomyelomeningocoeles, tumour excisions and untethering of filum terminale. In three patients, stimulation of the filum terminale elicited motor responses and, hence, it was not sectioned. Intraoperative mapping of the S2-4 nerve roots under controlled muscle relaxation is feasible in a majority of patients, including those with deficits involving S2-4. This method was useful in sparing viable nerve roots during surgery in conus and cauda equina regions, and identification of 'functional' filum terminale.

Saddle sensation is preserved in a few patients with cauda equina or conus medullaris lesions

Although saddle sensory deficit seems the most useful clinical sign in the diagnosis of a cauda equina or conus medullaris lesion, findings of previous studies were controversial. The aim of the present study was to try to resolve this issue. The data from the author's series of patients with clinical, electrodiagnostic and radiological findings compatible with a cauda equina lesion were reviewed. Of the 117 patients in the series, 11 (10 men) did not have a saddle sensory deficit. These 11 patients had less severe sacral dysfunction than the others, and none of them needed urgent surgical intervention. They all had electromyographic (EMG) signs of a significant motor fibre lesion, and in seven men the sacral (penilo-cavernosus) reflex was clinically abnormal. The study revealed normal saddle sensation in approximately 10% of patients with cauda equina or conus medullaris lesions. Dissociation between preserved touch sensation and abnormal EMG findings, as well as dissociation between preserved touch sensation and a non-elicitable penilo-cavernosus reflex might be explained by preservation of the thinner sensory nerve fibres, which are more resistant to compression. Although, saddle sensory loss seems to identify patients who might benefit from urgent spinal imaging and surgery, further diagnostic evaluation is also indicated in patients with normal saddle sensation, particularly due to the increased frequency of spinal tumours found in this subgroup.

Urethral sensory threshold and urethro-anal reflex latency in continent women

AIMS OF STUDY

The sensory evaluation of the lower urinary tract is summarized in the bladder proprioceptive sensitivity during cystometry. Experimental studies suggest that abnormalities of the urethral innervation and micturition reflex can be related to the presence of continence disturbances. This study aimed to measure the urethral sensory threshold and the urethro-anal reflex latency in healthy volunteers, establishing reading criteria, comparing the results and technique used with the literature and verifying the effect of physiological factors.

MATERIALS AND METHODS

Thirty healthy female volunteers were studied. They had an absence of genital or urinary complaints and had undergone no previous pelvic or vaginal procedures. The measurement of the urethral sensory threshold and urethro-anal reflex latency were performed as described.

RESULTS

The determination of the urethral sensory threshold and urethro-anal reflex latency were obtained in 96.6% of the volunteers. The electrophysiological parameters did not correlate with age, parity or number of vaginal deliveries. There was a positive association of the urethral sensory threshold with height. Technical aspects were considered and compared with those in the literature as well as the advantages and limitations of the method.

CONCLUSIONS

The measurement of the urethral sensory threshold and urethro-anal reflex latency presented consistent recordings. The urethral sensory threshold should be analyzed carefully in individuals with height above the population average. Subsequent observations are necessary to clarify their function in patients with continence disturbances and to measure the urethral function, but these values can be used as normal parameters for comparison.

Epidemiology of cauda equina and conus medullaris lesions

The epidemiology of cauda equina and conus medullaris lesions is not well known, and this study aimed to provide further information on this topic. In the period 1996-2004, patients fulfilling the clinical, electrodiagnostic, and radiological criteria for such lesions were identified. For cauda equina/conus medullaris lesions an annual incidence rate of 3.4/1.5 per million, and period prevalence of 8.9/4.5 per 100,000 population were calculated. The values obtained are probably valid estimates of the incidence and prevalence of these lesions in developed countries.

Neurophysiologic studies of the penilo-cavernosus reflex: Normative data

AIMS

To determine normative values for the penilo-cavernosus reflex on single and double pulse electrical, and mechanical stimulation.

METHODS

All men without neurologic disorder, with normal neurologic examination, and with bilaterally normal quantitative electromyography of the external anal sphincter muscles referred for sacral neurophysiologic studies in the years 2003-2005 were included. The penilo-cavernosus reflex was studied on single and double electrical, and mechanical stimulation. Responses were detected by a needle electrode inserted consecutively into the left and right bulbocavernosus muscle. In each subject, latency of the response, and using electrical stimulation, the sensory threshold, reflex threshold and stimulation strength, were determined. Normative values were calculated using parametric statistics and optimal data transformations.

RESULTS

In all 26 men with minor non-neurogenic sacral dysfunction reflex responses were recorded using each stimulation technique. Minimal latencies of reflex responses (in msec) were 29.88 +/- 5.65 (upper limit: 39.4), 30.00 +/- 4.11 (36.0), 28.16 +/- 5.80 (35.5) on single electrical, double electrical and mechanical stimulation, respectively. Sensory thresholds (in mA) were 7.80 +/- 2.73 (upper limit: 14.5) and 6.08 +/- 2.30 (10.5), and reflex thresholds (in mA) 25.36 +/- 11.04 (upper limit: 49.6) and 12.78 +/- 6.06 (26.9) on single and double electrical stimulation, respectively.

CONCLUSIONS

The obtained normative values for latency on single electrical and mechanical stimulation were similar to those previously published. Additional data on latency on double electrical stimulation, and on the sensory and reflex thresholds on single and double electrical stimulation are expected to increase the diagnostic utility of the penilo-cavernosus reflex.

Enhancement of the Bulbocavernosus Reflex During Intraoperative Neurophysiological Monitoring through the Use of Double Train Stimulation: A Pilot Study

OBJECTIVE

Electrophysiological bulbocavernosus reflex (BCR) testing, during surgeries in which the constituent neural components are at risk, might supplement other low sacral (S2-4) stimulation/recording techniques. However, intraoperative BCR is not always reliably implemented. We proposed to analyze BCR signals in five surgical patients monitored with the novel application of double train stimulation (DTS) to determine if the potential could be enhanced.

METHODS

We prospectively planned a regime of DTS BCR with a series of intertrain delays in five monitored patients at risk for low sacral neural injury. Patients were maintained with propofol, opiate infusion, and low inhalant anesthesia without muscle relaxant. Cutaneous sensory nerves of the penis (or clitoris) were stimulated using two consecutive pulse trains (DTS). Intertrain delays were 75, 100, 125, 150, 175, 200, and 250 ms. For BCR recording, uncoated paired wires were inserted into the external anal sphincter (EAS) bilaterally. For each trial, waveform amplitude, duration, and turn count measures for the first (single train) and second (double train) response were recorded. Percent increase/decrease of the second train response compared to the first train response was calculated.

RESULTS

There was at least a 30% increase in measures of amplitude, turn count, and duration of the second train response in 22/28, 22/28, and 14/28 of the total trials respectively. There was an insufficient number of independent observations to determine statistical significance.

CONCLUSIONS

Intraoperative BCR is currently obtained with some difficulty using pulse train stimulation. Our preliminary evidence has identified BCR waveform enhancement using DTS and suggests that the reliability of intraoperative BCR acquisition may be further improved by the addition of this technique. Our data are insufficient to define the best intertrain interval.

Physioanatomical relationship of the external anal sphincter to the bulbocavernosus muscle in the female

Both external anal sphincter (EAS) and bulbocavernosus muscle (BCM) have been shown anatomically and physiologically to constitute one muscle in males. We investigated the hypothesis that the EAS and BCM have similar anatomical pattern in females. The study consisted of cadaveric dissection, electromyographic recordings and inferior rectal nerve stimulation. Bulbocavernosus reflex action was performed in 16 healthy women before and after anesthetization of the EAS and BCM. The EAS extended forward across the perineal body and became continuous with the BCM in the labia majora. Glans clitoris (GC) or inferior rectal nerve stimulation effected synchronous EAS and BCM contractions with identical action potentials. GC stimulation while the EAS or BCM was anesthetized produced neither EAS nor BCM response. Similarly, stimulation of the anesthetized GC produced no EAS or BCM response. The BCM and EAS apparently constitute a single muscle, which seems to play dual and yet synchronous roles in fecal control and sexual response.