Bladder dysfunction in patients with cauda equina lesions

Evaluation of the role of anal tone and perianal sensation examination in the assessment of suspected cauda equina syndrome

PURPOSE

Cauda equina syndrome (CES) can present with a varied constellation of clinical signs and symptoms, which together with the time-sensitive nature of the condition and risk of catastrophic clinical outcome, presents a significant challenge to those assessing patients with this suspected diagnosis. Anal tone is commonly tested during initial assessment using a digital rectal examination (DRE). This study aims to evaluate the diagnostic value of anal tone and perianal sensation assessment in patients with suspected CES and report modern prevalence data on CES within a neurosciences centre.

MATERIALS AND METHODS

Consecutive patients with suspected CES presenting over three years to the Emergency Department (ED) of a busy tertiary centre were included in the study. History and examination findings, documented in the ED notes, were assessed and these variables were correlated with the presence or absence of cauda equina compression on subsequent magnetic resonance imaging (MRI).

RESULTS

Out of 1005 patients with suspected CES, 117 (11.6%) had MRI confirmed cauda equina compression (MRI + ve CES). 35% of MRI + ve patients and 31% of MRI -ve patients had reduced anal tone. Using univariate and multivariable logistic regression analyses, no associations were found between abnormal anal tone and MRI + ve CES for patients of all ages. The univariate logistic regression analysis identified altered perianal sensation to be significantly associated with MRI + ve CES in patients ≤42 years old. This association was no longer present when an adjusted multivariable logistic regression was performed.

CONCLUSION

The prevalence of MRI + ve CES was 11.6%. Our findings suggest that the clinical finding of reduced anal tone has no demonstrable diagnostic value for those with suspected CES, either in itself or in combination with other clinical findings. Further studies are needed to confirm the diagnostic efficacy of assessing perianal sensation in this context.

Treatment Outcomes of Lower Urinary Tract Symptoms due to Fragility Sacral Fractures: A Review of Eight Patients and Literature

BACKGROUND

Sacral fractures can cause lower urinary tract symptoms (LUTS) due to damage to the cauda equina. While several studies have reported on sacral fractures due to high-energy trauma, those due to fragility fractures have only been reported in case reports and their clinical differences are not well known. This study aimed to investigate the clinical characteristics of LUTS caused by fragility sacral fractures and propose a novel treatment strategy.

METHODS

This study is retrospective, uncontrolled, clinical case series. The inclusion criteria were sole sacral fractures due to low-energy trauma and appearance of LUTS after injury. Patients with additional spinal fractures or combined abdominal or pelvic organ injuries that could cause LUTS were excluded. Improvement in LUTS, period from onset to improvement, and imaging findings were recorded.

RESULTS

Eight patients met the inclusion criteria (4 surgical and 4 conservative treatment cases). Six patients showed improvement in LUTS. In surgical cases, the mean period from onset of LUTS to surgery and from onset of LUTS to improvement was 14.5 and 21.5 days, respectively. Intraoperative rupture or laceration of the dural sac was not observed. In 2 conservatively improved cases, the period from onset to improvement of LUTS was 14 and 17 days.

CONCLUSIONS

LUTS can improve even with conservative treatment and should be utilized as the primary choice. LUTS caused by severe sacral canal deformity and stenosis can be reversible, and the decision to perform surgical treatment is still timely if LUTS do not improve with conservative treatment for several weeks.

How to assess the long-term recovery outcomes of patients with cauda equina syndrome before surgery: a retrospective cohort study

BACKGROUND

Factors influencing recovery after decompression surgery for cauda equina syndrome (CES) are not completely identified. The authors aimed to investigate the most valuable predictors (MVPs) of poor postoperative recovery (PPR) in patients with CES and construct a nomogram for discerning those who will experience PPR.

METHODS

Three hundred fifty-six patients with CES secondary to lumbar degenerative diseases treated at Xijing Hospital were randomly divided into training ( N =238) and validation ( N =118) cohorts at a 2:1 ratio. Moreover, 92 patients from the 970 th Hospital composed the testing cohort. Least Absolute Shrinkage and Selection Operator regression (LASSO) was used for selecting MVPs. The nomogram was developed by integrating coefficients of MVPs in the logistic regression, and its discrimination, calibration, and clinical utility were validated in all three cohorts.

RESULTS

After 3 to 5 years of follow-up, the residual rates of bladder dysfunction, bowel dysfunction, sexual dysfunction, and saddle anesthesia were 41.9, 44.1, 63.7, and 29.0%, respectively. MVPs included stress urinary incontinence, overactive bladder, low stream, difficult defecation, fecal incontinence, and saddle anesthesia in order. The discriminatory ability of the nomogram was up to 0.896, 0.919, and 0.848 in the training, validation, and testing cohorts, respectively. Besides, the nomogram showed good calibration and clinical utility in all cohorts. Furthermore, the optimal cutoff value of the nomogram score for distinguishing those who will experience PPR was 148.02, above which postoperative outcomes tend to be poor.

CONCLUSION

The first pretreatment nomogram for discerning CES patients who will experience PPR was developed and validated, which will aid clinicians in clinical decision-making.

Serial transurethral cystometry: A novel method for longitudinal evaluation of reflex lower urinary tract function in adult female rats

AIMS

The aim of the study is to develop a minimally invasive method for longitudinal evaluation of lower urinary tract function that allows for simultaneous measurements of bladder pressure and external urethral sphincter (EUS) electromyographic (EMG) activity.

METHODS

To evaluate the reliability of serial transurethral cystometry (STUC), rats (n = 12) underwent three sessions of STUC, one session a week for 3 weeks. During each session, rats were anesthetized with ketamine-xylazine (90 mg/kg and 10 mg/kg), and micturition reflex data were acquired using transurethral cystometry and percutaneous recording of EUS (EMG) activity during continuous infusion of saline into the bladder. The reliability and consistency of the STUC method were assessed using intra-class correlation (ICC) analysis and repeated measures ANOVA.

RESULTS

ICC values calculated from five successive events during the first micturition session indicate good to excellent reliability for measurements of peak bladder pressure, threshold bladder pressure, minimum bladder pressure, volume threshold, duration of EUS bursting, and number of EUS burst events. Across the three recording sessions no significant difference was observed in peak bladder pressure, threshold bladder pressure, minimum bladder pressure, volume threshold, number of EUS burst events, and duration of EUS bursting using repeated measures ANOVA.

CONCLUSION

Serial transurethral cystometry under ketamine-xylazine anesthesia with simultaneous percutaneous EUS EMG recording is a novel, reliable, accurate, and minimally invasive method for quantitative assessment of lower urinary tract (LUT) function in adult female rats over extended periods of time.

Factors affecting urinary outcome after delayed decompression in complete cauda equina syndrome: "A regression model study"

PURPOSE

To evaluate the recovery of urinary functions and the factors predicting urinary recovery, following delayed decompression in complete cauda equina syndrome (CESR) secondary to Lumbar disc herniation (LDH).

METHODS

Retrospective study evaluated 19 cases of CESR due to single-level LDH, all presenting beyond 72 h. Mean delay in decompression was 11.16 ± 7.59 days and follow-up of 31.71 ± 13.90 months. Urinary outcomes were analysed on two scales, a 4-tier ordinal and a dichotomous scale. Logistic regression analysis was used for various predictors including delay in decompression, age, sex, radiation, level of LDH, motor deficits, type and severity of presentation. Time taken to full recovery was correlated with a delay in decompression. using Spearman-correlation.

RESULTS

Optimal recovery was seen in 73.7% patients and time to full recovery was moderately correlated with a delay in decompression (r = 0.580, p = 0.030). For those with optimal bladder recovery, mean recovery time was 7.43 ± 5.33 months. Time to decompression and other evaluated factors were not found contributory to urinary outcomes on either scales. Three (15.8%) patients had excellent, 11 (57.9%) had good, while 3 (15.8%) and 2 (10.5%) had fair and poor outcomes respectively.

CONCLUSIONS

Occurrence of CESR is not a point of no-return and complete recovery of urinary functions occur even after delayed decompression. Longer delay leads to slower recovery but it is not associated with the extent of recovery. Since time to decompression is positively correlated with time to full recovery, early surgery is still advised in the next available optimal operative setting.

LEVEL OF EVIDENCE

IV.

Neurogenic Bladder: Epidemiology, Diagnosis, and Management

Lower urinary tract dysfunction is a common sequel of neurological disease resulting in symptoms that significantly impacts quality of life. The site of the neurological lesion and its nature influence the pattern of dysfunction. The risk for developing upper urinary tract damage and renal failure is considerably lower in patients with slowly progressive nontraumatic neurological disorders, compared with those with spinal cord injury or spina bifida. This acknowledged difference in morbidity is considered when developing appropriate management algorithms. The preliminary evaluation consists of history taking, and a bladder diary and may be supplemented by tests such as uroflowmetry, post-void residual measurement, renal ultrasound, (video-)urodynamics, neurophysiology, and urethrocystoscopy, depending on the clinical indications. Incomplete bladder emptying is most often managed by intermittent catheterization, and storage dysfunction is managed by antimuscarinic medications. Intra-detrusor injections of onabotulinumtoxinA have revolutionized the management of neurogenic detrusor overactivity. Neuromodulation offers promise for managing both storage and voiding dysfunction. In select patients, reconstructive urological surgery may become necessary. An individualized, patient-tailored approach is required for the management of lower urinary tract dysfunction in this special population.

Cauda Equina Syndrome: A Review of 15 Patients Who Underwent Percutaneous Transforaminal Endoscopic Lumbar Discectomy (PTELD) Under Local Anaesthesia

INTRODUCTION

To analyse the results of Cauda Equina Syndrome (CES) operated by Percutaneous Transforaminal Endoscopic Lumbar Discectomy (PTELD).

MATERIAL AND METHODS

The study is a retrospective series of 15 patients operated by PTELD. Bladder dysfunction was classified as incomplete CES (CESI) and complete CES retention (CESR). Bladder / motor recovery rate and its timing, Oswestry Disability Index (ODI), Visual Analogue Score (VAS), patient satisfaction index, and sexual dysfunction were used to measure the outcome objectively. Additionally, in CESR patients, post-void residual (PVR) urine was measured by sonography. Complications and technical problems were noted.

RESULTS

There were ten patients of CESI and five patients of CESR. The average follow-up was 20.33(12.05) months. Bladder symptoms recovery was 100%, and motor recovery was 80%. VAS for back pain recovered to 0.53(0.52) from 8(2.39). VAS for leg pain recovered to 0.13(0.35) from 9.20(1.32). ODI improved to 6.07(2.85) from 77.52(13.20). The time to the recovery of bladder function was 1.47(1.55) days. All CESR patient's abnormal PVR urine was normalised at five weeks post-operative. No complications were reported. However, five technical executional problems occurred.

CONCLUSION

PTELD can be considered for CES treatment due to its substantial and quick recovery advantages. However, more evidence support is needed to make it a practice recommendation.

Lower urinary tract dysfunction in common neurological diseases

The lower urinary tract has the main function of urine storage and voiding. The integrity of the lower urinary tract nerve supply is necessary for its proper function. Neurological disorders can lead to lower urinary tract dysfunction (LUTD) and cause lower urinary tract symptoms (LUTS). Common causes of neurogenic LUTS or LUTD include spinal cord injury, multiple sclerosis, Parkinson's disease, cerebrovascular accidents, cauda equina syndrome, diabetes mellitus, and multiple system atrophy. The pathophysiology is categorized according to the nature of the onset of neurological disease. Assessment requires clinical evaluation, laboratory tests, imaging, and urodynamic studies. Impaired voiding is most often managed by clean intermittent self-catheterization if the postvoid residual urine exceeds 100 ml, whereas storage symptoms are most often managed by antimuscarinic medications. Intradetrusor injection of botulinum toxin type A is emerging as an effective treatment for managing refractory neurogenic detrusor overactivity. This review provides an overview of the clinical characteristics, diagnosis, and management of LUTD in patients with central and peripheral common neurological diseases.

Time Factor and Disc Herniation Size: Are They Really Predictive for Outcome of Urinary Dysfunction in Patients With Cauda Equina Syndrome?

BACKGROUND

Timing of surgery and the importance of the size of disc prolapse in cauda equina syndrome (CES) remain controversial.

OBJECTIVE

To investigate whether there is a relationship between postoperative urinary function, preoperative duration of neurogenic lower urinary tract dysfunction (NLUTD), and the level of canal compromise.

METHODS

Seventy-one patients operated for CES were prospectively identified between 2010 and 2013. Fifty-two cases with preoperative NLUTD were included. The "Prolapse: Canal ratio" (PCR) was calculated as a proportion of cross-sectional area of disc prolapse on total cross-sectional area of spinal canal.

RESULTS

Median of preoperative duration of NLUTD was 72 h (48; 132) and period from first assessment to surgery 10.5 h (7; 18.5). Urinary incontinence was seen in 46.2% of patients, 38.4% had painless retention and 15.4% had painful retention. In 38.5% of cases, urinary symptoms persisted for more than 20 mo postoperatively. There was no correlation between duration of preoperative NLUTD and urinary dysfunction persistence (P = .921). The outcome was not significantly influenced by having surgery more than the 48 h after presentation (P = .135). Preoperative incontinence persisted in 58% and painless retention in 30% of cases. The mean PCR was 0.6 ± 0.18. There was no correlation between PCR and outcome (P = .537) even after adjusting for duration of preoperative NLUTD (P = .7264).

CONCLUSION

No significant correlation was demonstrated between the preoperative duration of urinary dysfunction, the size of disc herniation relative to size of spinal canal, and postoperative urinary function in a large consecutive series of patients with CES.

MDCT Imaging of Acute Bladder Pathology

In this review, we will discuss and illustrate the pathophysiology, presentation, and multidetector computed tomography findings associated with emergent bladder conditions, limiting our discussion to traumatic, infectious, and obstructive etiologies. After reviewing computed tomography cystographic technique, the commonly utilized classification systems for bladder trauma will be presented with illustrative examples of associated typical and more infrequent secondary injuries and complications. Next, the pathogenesis and imaging appearance of both mechanical and neurogenic acute urinary retention will be addressed, including less common though potentially pathognomonic obstructive etiologies including urethral calculi and ectopic ureteroceles. Finally, we will review and illustrate the imaging features of both inflammatory and infectious cystitis, including hemorrhagic and emphysematous variants, as well as the potentially encountered secondary complications.

Soft Artificial Bladder Detrusor

Developing soft devices for invasive procedures bears great importance for human health. The softness and large strain actuation of responsive hydrogels promise the potential to fabricate soft devices, which can attach on and assist to the function of organs. The key challenges lie in the fabrication of soft devices with robust actuating ability and biocompatibility to the attached organ. This paper presents a solution that integrates the thermoresponsive hydrogel membrane with flexible electronics and silk scaffold into a balloon-like soft device. As an example, the actuation assisting function of this soft device for shrinking an animal bladder is presented. The mechanical behaviors of the balloon-like soft device are experimentally and theoretically investigated. The concepts are applicable to other applications such as soft implants, soft robotics, and microfluidics.

Reconstruction of bladder function and prevention of renal deterioration by means of end-to-side neurorrhaphy in rats with neurogenic bladder

AIMS

To investigate the feasibility of restoring bladder function and prevention of renal deterioration by neurorrhaphy in rats with neurogenic bladder (NB).

METHODS

Forty-two rats were assigned to the end-to-side nerve coaptation group (ECG, n = 16), no nerve coaptation group (NCG, n = 16), and control group (CG, n = 10). In the ECG, the left ventral root (VR) and dorsal root (DR) of L6 and S1 were transected, and the distal stump of L6VR was sutured to the lateral face of L4VR. In the NCG, the left VR and DR of L6 and S1 were transected, but coaptation was not performed. In the CG, no operation was performed. Nerve regeneration, bladder function, and renal function were evaluated by FluoroGold (FG) retrograde tract tracing, cystometry, electrical stimulation, MRI, histology and biochemical assays.

RESULTS

In the ECG, FG-labeled neurons were observed in the left ventral horn of L4 spinal cord. There was a significant increase in intravesical pressure upon stimulation of the left L4VR proximal to the coaptation. Maximum cystometric capacity, post-void residual urine, bladder compliance and weight, serum creatinine, blood urea nitrogen, and fibrotic area of bladder and kidney were lower in the ECG than in the NCG, but higher than the CG. Hydronephrosis was noticed in ECG and NCG rats. Maximum detrusor voiding pressure was higher in the ECG and CG than in the NCG.

CONCLUSIONS

End-to-side neurorrhaphy is a useful method for restoring bladder function and preventing renal injury in rats with NB.

Impact of bladder, bowel and sexual dysfunction on health status of people with thoracolumbar spinal cord injuries living in the community

OBJECTIVE

The disruption of autonomic function following a spinal cord injury (SCI) is common and can negatively affect quality of life. The objective of this study was to describe the prevalence of bladder/bowel incontinence and sexual dysfunction in community-dwelling individuals with a thoracolumbar SCI and examine the impact on general physical and mental health status.

METHODS

Participants who sustained a traumatic SCI to the thoracolumbar region of the spinal cord and classified as American Spinal Injury Association Impairment Scale (AIS) A to D were recruited. Demographic, injury data, MRI classification and neurological data were collected on admission. At follow-up, the neurological data, a questionnaire collecting participant-reported secondary health conditions (SHCs) (e.g. bladder incontinence, depression etc.) following SCI and health status measured by Short Form-36 were obtained. Regression models determined the association of health status with demographic/injury-related data, types and number of SHCs.

RESULTS

Of the 51 participants, 58.8% reported bladder incontinence, 54.0% bowel incontinence, 60.8% sexual dysfunction and 29.4% had all three. The regression models demonstrated that age at injury, bowel incontinence, sexual dysfunction, presence of pain, motor score at follow-up and the number of SHCs were significant predictors of health status. The number of SHCs was more predictive than all other demographic and injury variables for health status.

CONCLUSION

Results highlight the high prevalence of self-reported bowel/bladder incontinence and sexual dysfunction in the traumatic thoracolumbar SCI population and support the need for standardized assessments. Several demographic, injury-related and SHCs impacted health status and should be considered for the management of individuals living in the community.

Spinal Cord Injury Clinical Registries: Improving Care across the SCI Care Continuum by Identifying Knowledge Gaps

Timely access and ongoing delivery of care and therapeutic interventions is needed to maximize recovery and function after traumatic spinal cord injury (tSCI). To ensure these decisions are evidence-based, access to consistent, reliable, and valid sources of clinical data is required. The Access to Care and Timing Model used data from the Rick Hansen SCI Registry (RHSCIR) to generate a simulation of healthcare delivery for persons after tSCI and to test scenarios aimed at improving outcomes and reducing the economic burden of SCI. Through model development, we identified knowledge gaps and challenges in the literature and current health outcomes data collection throughout the continuum of SCI care. The objectives of this article were to describe these gaps and to provide recommendations for bridging them. Accurate information on injury severity after tSCI was hindered by difficulties in conducting neurological assessments and classifications of SCI (e.g., timing), variations in reporting, and the lack of a validated SCI-specific measure of associated injuries. There was also limited availability of reliable data on patient factors such as multi-morbidity and patient-reported measures. Knowledge gaps related to structures (e.g., protocols) and processes (e.g., costs) at each phase of care have prevented comprehensive evaluation of system performance. Addressing these knowledge gaps will enhance comparative and cost-effectiveness evaluations to inform decision-making and standards of care. Recommendations to do so were: standardize data element collection and facilitate database linkages, validate and adopt more outcome measures for SCI, and increase opportunities for collaborations with stakeholders from diverse backgrounds.

Urogenital Symptoms in Neurologic Patients

PURPOSE OF REVIEW

Lower urinary tract and sexual dysfunction are commonly reported sequelae of neurologic disease and have a significant impact on quality of life. This article presents an up-to-date summary of the clinical presentation, investigations, and treatment options for urogenital dysfunction in patients with neurologic disease.

RECENT FINDINGS

The pattern of lower urinary tract dysfunction is influenced by the site of the neurologic lesion. The risk for developing upper urinary tract damage is considerably less in patients with slowly progressive nontraumatic neurologic disorders, as compared to those with spinal cord injury or spina bifida. Investigations such as urinalysis, ultrasonography, and urodynamics provide further information about the cause and nature of lower urinary tract dysfunction. Antimuscarinic agents are the first-line management of urinary incontinence; however, side effect profile and anticholinergic burden should be considered when prescribing medications. β3-Adrenergic receptor agonists are a promising alternative oral medication. Tibial and sacral neuromodulation have been shown to be effective for managing incontinence, as well as urinary retention due to Fowler syndrome. Intradetrusor injections of onabotulinumtoxinA have revolutionized the management of neurogenic detrusor overactivity.

SUMMARY

Neurologic patients reporting urogenital symptoms require a comprehensive evaluation for planning a patient-tailored approach to management. Neurologists are increasingly inquiring about lower urinary tract and sexual functions and becoming involved in the management of these disorders.

[Neonatal genital prolapse: an exceptional entity (about a case)]

Neonatal genital prolapse is an uncommon entity. It is usually associated with birth defects of the central nervous system. We here report the case of a full term newborn with a genital prolapse not associated with central nervous system abnormalities in order to highlight the diagnostic and therapeutic particularity of this very rare disease.

Examination of The Predictive Power of Electromyography and Urodynamic Study in Patients with Cauda Equina Syndrome (Horse Tail Syndrome)

Background:

Cauda equina syndrome is a rare disorder that causes loss of Lumbar plexus function (nerve roots) lower than conus medullaris. No risk factor has been defined for this disease yet. Due to the high morbidity of Cauda equina syndrome and lack of sufficient information about the connection between the disease and urodynamic findings and EMG (Electromyography) findings, the need for this comprehensive study is felt.

Objective:

The aim is to determine the predictive power of findings resulted from urodynamics and electromyography of perineal region and around sphincter in the clinical cure rate of urination in patients with urinary retention followed by Cauda equina syndrome.

Method:

Patients referred to Shohadaye Tajrish Hospital during the years 2009 to 2013, in case of having Cauda equina syndrome symptoms (confirmed with Lumbar MRI), were undergone urodynamic examination and perineal electromyography after surgical decompression action. These both assessments (urodynamic study and electromyography) were repeated during the follow-up of 15 patients in the first and sixth months after surgery and findings were compared with each other.

Results:

Among the Urodynamic findings, Qmax (maximum urine flow) during three studies had a significant relationship with long-term recovery rate of patients (P <0.05). The relationship had been more valuable in follow-ups after one month (P = 0.0001). Also, BCI (Bladder Contractility Index) in all three studies had a significant relationship with clinical improvement in the ability to urinate (P <0.001). The residual urine (PVR) compared to two previous urodynamic findings showed a less significant relationship with clinical cure rate (P = 0.04). Among the findings of muscle-nerve (MUAP Fibrillation, Positive sharp way) none of them had a significant relationship with cure rate.

Conclusion:

Urodynamic finding, especially Qmax and bladder contractility index, can be considered as predictive indicators for patients’ recovery after surgery.

The Role of Urodynamics in Elderly Patients

Urodynamic testing is the study of the function of the bladder and its outlet. Geriatric patients are at greater risk for lower urinary tract dysfunction owing to age or neurologic disease, such as Parkinson disease or stroke. Although urodynamic testing may best diagnose an individual patient's bladder storage and emptying function, the tests should be tailored to answer the question being asked and the test should only be done when the outcome of the test is going to impact decision making regarding management or treatment.

Lower urinary tract dysfunction in the neurological patient: clinical assessment and management

Lower urinary tract (LUT) dysfunction is a common sequela of neurological disease, resulting in symptoms that have a pronounced effect on quality of life. The site and nature of the neurological lesion affect the pattern of dysfunction. The risk of developing upper urinary tract damage and renal failure is much lower in patients with slowly progressive non-traumatic neurological disorders than in those with spinal cord injury or spina bifida; this difference in morbidity is taken into account in the development of appropriate management algorithms. Clinical assessment might include tests such as uroflowmetry, post-void residual volume measurement, renal ultrasound, (video-)urodynamics, neurophysiology, and urethrocystoscopy, depending on the indication. Incomplete bladder emptying is most often managed by intermittent catheterisation, and storage dysfunction by antimuscarinic drugs. Intradetrusor injections of onabotulinumtoxinA have transformed the management of neurogenic detrusor overactivity. Neuromodulation offers promise for managing both storage and voiding dysfunction. An individualised, patient-tailored approach is required for the management of LUT dysfunction associated with neurological disorders.

Lower urinary tract dysfunction in patients with peripheral nervous system lesions

The prevalence of lower urinary tract (LUT) dysfunction in peripheral nervous system (PNS) disorders is larger than in comparable control populations. This is particularly true for polyneuropathies with autonomic nervous system involvement, and for localized lesions with LUT innervation. LUT symptoms may be the guide to the diagnosis of processes localized in the lumbosacral spinal canal (as in cauda equina syndrome), and in the pelvis. Typical LUT dysfunctions (LUTD) caused by PNS involvement include bladder and sphincter hypoactivity with poor emptying, and incontinence. Paradoxically, bladder overactivity may also occur in pure PNS lesions. The acute cauda equina syndrome is an emergency requiring magnetic resonance imaging and surgery; in chronic neurogenic LUTD due to PNS involvement, the diagnosis of the lesion may be clarified by clinical neurophysiologic testing. Other important causes of neurogenic LUT dysfunction are perineoabdominal and pelvic surgeries. Surgeons are devising nerve-sparing techniques to prevent such major and often persistent complications in patients who are otherwise cured of the underlying disease. LUTD significantly affects the quality of life in patients and may lead to recurring urinary infections and upper urinary tract involvement. Thorough assessment of LUT function by urodynamics may be necessary in patients who are not improved by simple conservative measures.

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.

Sexual dysfunction in patients with peripheral nervous system lesions

Peripheral nervous system (PNS) disorders may cause sexual dysfunction (SD) in patients of both genders. These disorders include mainly polyneuropathies (particularly those affecting the autonomic nervous system (ANS)) and localized lesions affecting the innervation of genital organs. Impaired neural control may produce a malfunction of the genital response consisting of loss of genital sensitivity, erectile dysfunction, loss of vaginal lubrication, ejaculation disorder, and orgasmic disorder. In addition, there is often a loss of desire which actually has a complex pathogenesis, which goes beyond the mere loss of relevant nerve function. In patients who have no manifest health problems - particularly men with erectile dysfunction - one should always consider the possibility of an underlying polyneuropathy; in patients with SD after suspected denervation lesions of the innervation of genital organs within the lumbosacral spinal canal and in the pelvis, clinical neurophysiologic testing may clarify the PNS involvement. SD can alter self-esteem and lower patients' quality of life; opening up a discussion on sexual issues should be a part of the management of patients with PNS disorders. They may greatly benefit from counseling, education on coping strategies, and specific treatments.

Bladder dysfunction in presymptomatic gene carriers and patients with Huntington's disease

The objective of this study was to report bladder dysfunction and cystometric findings in a systematically studied cohort of Huntington's disease (HD) patients. In HD patients and asymptomatic HD gene carriers a urinary function questionnaire, neurologic assessment using the Unified Huntington's Disease Rating Scale, and postvoid residual volume measurement were applied. All patients were also invited to cystometric studies. Urinary function data were compared to control men and women. The most common symptoms in 54 HD patients (24 men) were those of bladder overactivity (men/women 54%/40%), followed by urinary incontinence (29%/43%) and symptoms of disturbed bladder emptying (25%/40%). Using urinary function questionnaires severe bladder dysfunction was found in 4%/0%, moderate in 21%/23%, and mild in 25%/30% of HD men/women. Urinary symptoms interfered with daily life in 21%/37% and sexual life in 21%/33% of sexually active HD men/women. In 5 HD men and 1 woman, increased postvoid residual volume (>100 ml) was found. Compared to 49/55 control men/women urinary incontinence, and urgency were more common in HD men, but not in HD women (urinary incontinence reported 10%/38% of control men/women). Cystometry, performed in 12 HD patients and 1 of 10 asymptomatic HD gene carriers, demonstrated detrusor-sphincter dyssynergia in 5 (42%), detrusor overactivity in 2 (17%), and reduced detrusor capacity in 2 (17%) HD patients. Our study demonstrated significant urinary symptoms in HD patients, which reduced their quality of life. Physicians helping HD patients should also consider this largely neglected aspect of the disease.

Acupuncture for neurogenic bladder due to spinal cord injury: a systematic review protocol

INTRODUCTION

Neurogenic bladder is one of the most common complications following spinal cord injury (SCI). In China, acupuncture therapy is a common treatment for neurogenic bladder due to SCI, but its effects and safety remain uncertain. A protocol is described for a systematic review to investigate the beneficial effects and safety of acupuncture for neurogenic bladder due to SCI.

METHODS AND ANALYSIS

Eight databases will be searched from their inception: the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, the China National Knowledge Infrastructure (CNKI), the VIP database, the Wanfang database, the China Doctoral Dissertations Full-text Database (CDFD) and the China Master's Theses Full-text Database (CMFD). Any clinical randomised controlled trials (RCTs) and the first period of randomised cross-over studies related to acupuncture for neurogenic bladder due to SCI will be included. Outcomes will include change in urinary symptoms, urodynamic tests, clinical assessment and quality of life (QoL). The incidence of adverse events will be assessed as the safety outcome. Study selection, data extraction and quality assessment will be performed independently by two reviewers. Assessment of risk of bias, data synthesis and subgroup analysis will be carried out using Review Manager software.

ETHICS AND DISSEMINATION

Ethics approval is not required as this is a protocol for a systematic review. The findings of this systematic review will be disseminated via peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

PROSPERO (CRD42014010448).

Detrusor overactivity in patients with cauda equina syndrome

STUDY DESIGN

Retrospective cross-sectional study.

OBJECTIVE

To delineate the neurogenic bladder type in patients with cauda equina syndrome (CES) and to suggest, in light of the clinical, radiological, and electrophysiological findings, a possible cause of bladder dysfunction.

SUMMARY OF BACKGROUND DATA

Many patients with CES experience bladder dysfunction, although the type of neurogenic bladder is quite variable in the clinical setting. Bladder dysfunction in patients with CES is usually areflexic or acontractile detrusor. However, detrusor overactivity (DOA) also reported the cases that cannot be explained by pure root injuries in the cauda equina region.

METHODS

Patients with CES with neurogenic bladder were studied, all of whom (n = 61; mean age ± SD, 48.0 ± 15.9 yr) underwent urodynamic analysis, magnetic resonance imaging (MRI), and electrophysiology. According to the urodynamic findings, the neurogenic bladder was classified into 2 types: DOA and detrusor underactivity or acontractility. The highest level of injury (HLI) or level of injury was determined and analyzed on the basis of the clinical-urodynamic and electrophysiological findings, respectively.

RESULTS

Twenty patients with CES (32.8%) showed DOA; in most of them (85.0%, 17/20 patients), the HLI on electrophysiological assessment was L2 or above. Forty-one patients with CES showed detrusor underactivity or acontractility; and most of the patients with CES whose HLI was L3 or below showed detrusor underactivity or acontractility (91.2%, 31/34 patients). None of the HLI or level of injury from the clinical or magnetic resonance imaging findings correlated with neurogenic bladder type. We also found that urodynamic findings including maximal detrusor pressure and bladder capacity was partially correlated with the HLI on electrophysiological assessment (r² = 0.244, P < 0.001 and r² = 0.330; P < 0.001, respectively).

CONCLUSION

DOA was seen most often in patients with CES whose HLI was L2 or above, and might be associated with combined conus medullaris lesion. Electrophysiology might be the most useful assessment tool for prediction of neurogenic bladder type in patients with CES.

Urodynamic profile of patients with neurogenic bladder following non-traumatic myelopathies

Objective:

To observe the urodynamic profile of the patients following non-traumatic myelopathies (NTMs) with neurogenic bladder.

Setting:

Neurological rehabilitation department of university tertiary research hospital.

Materials and Methods:

Seventy-nine patients (44 men) with monophasic NTM, with the age range 8-65 years (31.0 ± 16.0 years), were admitted for inpatients’ rehabilitation. Length of stay in rehabilitation ranged from 6 to 120 days (32.0 ± 24.8 days). Fifty-six patients (70.9%) had spinal lesion above D10, 17 had lesion between D10 and L2 (21.5%), and 6 (7.6%) had cauda equina syndrome. All patients had neurogenic bladder with urinary complaints. Urodynamic study (UDS) was performed in all patients.

Results:

UDS showed 71.4% patients (40/56) had neurogenic detrusor overactivity (NDO) with or without sphincter dyssynergy (DSD) with lesion above D10; only 52.9% patients (9/17) had NDO with or without DSD detrusor with lesion between D10 and L2; and majority (5/6 patients) had underactive detrusor in the cauda equina group. Bladder management was based on the UDS findings. No significant correlation was found (P > 0.05) between detrusor behavior and the level, severity (ASIA Impairment Scale) of spinal injury, or gender using chi-square test.

Conclusions:

Neurogenic bladder following NTM was observed in all patients. UDS suggested predominantly NDO in lesions above D10 and mixed pattern in between D10 and L2 lesions. No significant correlation was found between detrusor behavior and the level or severity of NTM in the study.

Bladder dysfunction and urodynamic study in tuberculous meningitis

BACKGROUND

Micturitional disturbances in tuberculous meningitis have been reported infrequently and that too without urodynamic studies. Bladder dysfunction in tuberculous meningitis is often considered secondary to tuberculous radiculomyelopathy. We, in this study, evaluated the incidence and pattern of bladder dysfunction in tuberculous meningitis.

MATERIALS AND METHOD

In this prospective study, 51 patients were included. In addition to clinical evaluation, patients were subjected to a urodynamic study along with magnetic resonance imaging (MRI) of brain and spine. Patients were followed up for 6 months. A follow-up urodynamic study was performed after 6 months.

RESULTS

Out of 51 patients, urinary symptoms were present in one-third of the patients. Approximately, 70% (36) of the patients had urodynamic abnormalities. The commonest (22/51) urodynamic abnormality was detrusor hyporeflexia/areflexia. Other urodynamic abnormalities were neurogenic detrusor overactivity in 10, detrusor sphincter dyssynergia in 6, normal detrusor activity in 19, reduced bladder sensation in 12, raised cystometric capacity in 9, and larger volumes of post-void residual urine in 12 patients. Six patients were unable to void on command. Three patients with neurogenic detrusor overactivity had leak during study. MRI showed spinal meningeal enhancement in 37, lumbosacral arachnoiditis in 25, myelitis in 12 patients, CSF loculations in 6, and cord atrophy in 5 patients. Spinal arachnoiditis and urinary symptoms showed significant association with urodynamic abnormalities. Follow-up urodynamic study showed resolution of urodynamic abnormalities in 72.6% of the patients with treatment. Seven (28%) patients, with normal baseline urodynamic findings, paradoxically developed new abnormalities.

CONCLUSION

Bladder dysfunctions, in tuberculous meningitis, are frequently encountered. A significant association exists between urodynamic abnormalities and tuberculous lumbosacral arachnoiditis and myeloradiculopathy.

Complaints of micturition, defecation and sexual function in cauda equina syndrome due to lumbar disk herniation: a systematic review

PURPOSE

Cauda equina syndrome (CES) is a rare complication of lumbar disk herniation. Although micturition, defecation and/or sexual function are by definition affected, little seems to be known about long-term outcome. Aim of this study is to review current literature on outcome of micturition, defecation and sexual function in CES due to lumbar disk herniation.

METHODS

A literature search was done in Pubmed, Embase and Web of Science using a sensitive search string combination. Studies were selected by predefined selection criteria and risk of bias was assessed using a Cochrane checklist adjusted for this purpose.

RESULTS

Fifteen studies were included. Risk of bias varied with six studies showing low risk. Mean minimal follow-up time was 17.0 months (range 3-24 months). All studies evaluated micturition and reported dysfunction at follow-up in 42.5% (range 13.3-90.0%). Defecation and sexual function were evaluated in eight and nine studies, respectively, and reported to be 49.6 (range 10.5-90.0%) and 44.3% (range 10.0-76.6%), respectively. Only two studies assessed sexual function in all patients at follow-up.

CONCLUSION

This review offers an insight into the extent of micturition dysfunction, defecation dysfunction and sexual dysfunction (SD) in CES after decompression. Our findings show that dysfunction is extremely common, even at long-term follow-up. A condition as invalidating as CES requires proper patient information and the outcomes presented here may help in providing those data. Bias in included studies, lack of universal definitions and incomplete follow-up results qualify these data as the best we momentarily have, but still subject to improvement. Since SD seems to be severely underreported, we recommend further research to explore the extent of this problem, as well as the use of questionnaires in future clinical (prospective) studies to accomplish a more patient-based approach.

Can be sphincter electromyography reference values shared between laboratories?

AIMS

Sphincter electromyography (EMG) is an important method in diagnosis of neuropathic sacral lesions. Quantitative EMG analysis increases utility of the test, but requires valid reference values. Although commonly employed, validity of sharing reference data between electrodiagnostic laboratories has not been confirmed. In this study, this approach was assessed by comparing the reproducibility of data sets obtained by the same and different laboratories.

METHODS

Confidence intervals and sensitivity of motor unit potential (MUP) parameters in the external anal sphincter (EAS) muscles were calculated using data obtained from three different control groups of women (number of women: 41, 48, and 66), examined by the same (the first two groups) and another investigator (the third group). Sensitivities to diagnose neuropathic changes in a known patient group were compared.

RESULTS

When compared to the first reference group, the MUP parameter means of 2/7 (same investigator) versus 3/7 (different investigator) were significantly different. Similarly, 3/14 versus 4/14 MUP parameter outliers were different. Finally, 6/14 versus 7/14 sensitivities (using a combination of MUP parameter means and outliers) were different.

CONCLUSIONS

This study demonstrated somewhat larger differences between confidence intervals obtained by different investigators, as compared to those obtained by a single investigator. However, most of these differences can be explained by differences in recruited groups of women, and slight inconsistencies in applied techniques. Presented data suggest that confidence intervals from other laboratories can be used, but only if exact protocols from original normative studies are strictly followed.

Pelvic Nerve Injury Causes a Rapid Decrease in Expression of Choline Acetyltransferase and Upregulation of c-Jun and ATF-3 in a Distinct Population of Sacral Preganglionic Neurons

Autonomic regulation of the urogenital organs is impaired by injuries sustained during pelvic surgery or compression of lumbosacral spinal nerves (e.g., cauda equina syndrome). To understand the impact of injury on both sympathetic and parasympathetic components of this nerve supply, we performed an experimental surgical and immunohistochemical study on adult male rats, where the structure of this complex part of the nervous system has been well defined. We performed unilateral transection of pelvic or hypogastric nerves and analyzed relevant regions of lumbar and sacral spinal cord, up to 4 weeks after injury. Expression of c-Jun, the neuronal injury marker activating transcription factor-3 (ATF-3), and choline acetyltransferase (ChAT) were examined. We found little evidence for chemical or structural changes in substantial numbers of functionally related but uninjured spinal neurons (e.g., in sacral preganglionic neurons after hypogastric nerve injury), failing to support the concept of compensatory events. The effects of injury were greatest in sacral cord, ipsilateral to pelvic nerve transection. Here, around half of all preganglionic neurons expressed c-Jun within 1 week of injury, and substantial ATF-3 expression also occurred, especially in neurons with complete loss of ChAT-immunoreactivity. There did not appear to be any death of retrogradely labeled neurons, in contrast to axotomy studies performed on other regions of spinal cord or sacral ventral root avulsion models. Each of the effects we observed occurred in only a subpopulation of preganglionic neurons at that spinal level, raising the possibility that distinct functional subgroups have different susceptibility to trauma-induced degeneration and potentially different regenerative abilities. Identification of the cellular basis of these differences may provide insights into organ-specific strategies for attenuating degeneration or promoting regeneration of these circuits after trauma.

Cauda equina lesions as a complication of spinal surgery

Although the most common aetiology of cauda equina lesions is lumbar intervertebral disc herniation, iatrogenic lesions may also be the cause. The aim of this study was to identify and present patients in whom cauda equina lesions occurred after spinal surgery. From the author's series of patients with cauda equina lesions, those with the appearance of sacral symptoms after spinal surgery were identified. To demonstrate lesions more objectively, electrodiagnostic studies were performed in addition to history and clinical examination. Imaging studies were also reviewed. Of 69 patients from the series, 11 patients in whom a cauda equina lesion developed after spinal surgery were identified. The aetiology comprised surgery for herniated intervertebral disc in 5 (4 performed by a single surgeon), spinal stenosis surgery in 4, and postoperative lumbar epidural haematoma in 2 patients (each performed by a different surgeon). Proportion of spinal surgeries with this complication varied from 0 to 6.6 per thousand in different centres. Patients with iatrogenic cauda equina lesion were significantly older (p < 0.001), and reported more severe urinary, but similar bowel and sexual symptoms compared to other patients in the series. In conclusion the study identified spinal surgery as the cause of approximately 15% of cauda equina lesions. More than a third of lesions developed after procedures performed by a single surgeon. Most of the remaining lesions could probably be avoided by better surgical technique (e.g. the use of a high-speed drill instead of a Kerrison rongeur in patients with severe spinal stenosis), or prevented by closer postoperative monitoring (e.g. in patients with postoperative lumbar epidural haematoma).

Long-term implantation of deep brain stimulation electrodes in the pontine micturition centre of the Göttingen minipig

AIM

To implant deep brain stimulation (DBS) electrodes in the porcine pontine micturition centre (PMC) in order to establish a large animal model of PMC-DBS.

METHOD

Brain stems from four Göttingen minipigs were sectioned coronally into 40-mum-thick histological sections and stained with Nissl, auto-metallographic myelin stain, tyrosine hydroxylase and corticotrophin-releasing factor immunohistochemistry in order to identify the porcine PMC. DBS electrodes were then stereotaxically implanted on the right side into the PMC in four Göttingen minipigs, and the bladder response to electrical stimulation was evaluated by subsequent cystometry performed immediately after the operation and several weeks later.

FINDINGS

A paired CRF-dense area homologous to the PMC in other species was encountered in the rostral pontine tegmentum medial to the locus coeruleus and ventral to the floor of the fourth ventricle. Electrical stimulation of the CRF-dense area resulted in an increased detrusor pressure followed by visible voiding in some instances. The pigs were allowed to survive between 14 and 55 days, and electrical stimulation resulting in an increased detrusor pressure was performed on more than one occasion without affecting consciousness or general thriving. None of the pigs developed postoperative infections or died prematurely.

CONCLUSIONS

DBS electrodes can be implanted for several weeks in the identified CRF-dense area resulting in a useful large animal model for basic research on micturition and the future clinical use of this treatment modality in neurogenic supra-pontine voiding disorders.

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.

Neurophysiology of the neurogenic lower urinary tract disorders

The nervous system structures involved in the control of the lower urinary tract (LUT) are usually divided using a neuroanatomical classification system into suprapontine, pontine, spinal and sacral. In all patients with LUT symptoms, after exclusion of local causes, a nervous system disorder needs to be considered. For the diagnosis of neurogenic LUT disorders, in addition to clinical assessment, neurophysiologic testing might be useful. Imaging and other laboratory studies (e.g., cystometry) often provide relevant additional information. Neurophysiologic tests are more useful in patients with sacral compared with suprasacral disorders. Although in patients with LUT disorders external urethral sphincter (EUS) electromyography (EMG) would seem the most appropriate, anal sphincter EMG is the single most useful diagnostic test, particularly for focal sacral lesions, and atypical parkinsonism. Another clinically useful method that tests the sacral segments, and complements EMG, is the sacral (penilo/clitoro-cavernosus) reflex. Kinesiologic EMG is useful to demonstrate detrusor sphincter dyssynergia (i.e., increased EUS activity during bladder contraction), which is particularly common in spinal cord disease. Somatosensory evoked potential (SEP) and motor evoked potential (MEP) studies (cortical and lumbar) may be useful to diagnose clinically silent central lesions. MEP, in addition, seems to be very promising in research into cortical excitability. Theoretically, cortical SEP on bladder/urethra stimulation would be much more useful than pudendal SEP because it tests thin nerve afferents from the pelvic viscera. However, the utility of this technique is limited by technical difficulties, which can be partially overcome by the concomitant recording of a palmar sympathetic skin response (SSR). SSR recorded from the saddle region is also useful for testing the lumbosacral sympathetic system. Although the technique of detrusor EMG has been recently described in humans, a clinically useful test for evaluating the sacral parasympathetic system, which is crucial for LUT functioning, is still lacking.

Chapitre A-2 - Traitements pharmacologiques per-os à visée sphinctérienne en neuro-urologie

Sphincter dysfunction is an almost constant pathological process in neurourology. No oral pharmacological treatment is available to treat stress urinary incontinence secondary to sphincter incompetence or to relieve urethral hypertonia usually induced by detrusor-sphincter dyssynergia. The few treatments that induce sphincter relaxation are not sufficient to justify a routine therapeutic indication.

Chapitre E - Particularités du prolapsus génital de la blessée médullaire

This article discusses the particular problems of management of genital prolapse in women with neurogenic bladder. It seemed particularly important to emphasize the particular risks in this setting in view of the limited literature on the subject.

Chapitre D - Troubles vésico-sphinctériens et hernies discales

Lower urinary tract dysfunction related to herniated disk can raise complex diagnostic and management problems. This article reviews the two main clinical situations encountered: documented lower urinary tract dysfunction in a context of cauda equina syndrome secondary to herniated disk and lower urinary tract dysfunction representing the only clinical sign of herniated disk with no other alteration of the neurological examination. Regardless of the neurological signs, urodynamic assessment is essential to characterize any lower urinary tract dysfunction and to determine the modalities of long-term surveillance.

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.

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.