Anorectal function in patients with complete spinal transection before and after sacral posterior rhizotomy

Effect of neurogenic bowel dysfunction symptoms on quality of life after a spinal cord injury

BACKGROUND

Neurogenic bowel dysfunction (NBD) is a common problem among people with spinal injury; management of bowel dysfunction and related problems are considered significant factors in daily life after injury. But despite the critical relevance of bowel dysfunction in the daily life of SCI survivors, there have been few published studies on the management of NBD. So, this study aimed to describe the bowel programmers utilized by people with SCI in China and the impact of bowel dysfunction on the quality of life (QoL).

DESIGN

A cross-sectional online survey.

SETTING

Rehabilitation Medicine Department of Wuhan's Tongji Hospital.

PARTICIPANTS

SCI patients who had been diagnosed with neurogenic bowel dysfunction and who were receiving regular medical monitoring at the rehabilitation medicine department were invited to participate in our study.

OUTCOME MEASURES

A neurogenic bowel dysfunction (NBD) score is a questionnaire developed to evaluate the severity of neurogenic bowel dysfunction. A Short Form-12 (SF-12) was designed to measure the quality of life in people with SCI. Demographic and medical status information was extracted from their medical records.

RESULTS

The two questionnaires were sent to 413 SCI patients. Two hundred ninety-four subjects (43.1 ± 14.5 years of age; men, 71.8%) responded. Most of the respondents performed their bowel movement daily 153 (52.0%), a defecation time was 31-60 min among 70 (23.8%) of them, 149 (50.7%) used medication (drops or liquid) to treat constipation, and 169 (57.5%) used digital stimulation more than once per week to boost the bowel evacuation. This study found a significant association between the QoL score and the time used for each defecation, autonomic dysreflexia (AD) symptoms, taking medication to treat fecal incontinence, using digital stimulation, having uncontrollable flatus and perianal skin problems.

CONCLUSION

Management of bowel dysfunction is complex and associated with QoL in people with SCI. Items of the NBD questionnaire that greatly deteriorated the QoL were time in one defecation > 60 min, symptoms of AD during or before defecation, taking medication (drops or liquid), and using digital stimulation. Dealing with those problems can improve the life quality of spinal cord injury survivors.

[Analysis of anorectal manometry data in central and peripheral neurological deseases: Review of the literature]

INTRODUCTION

Peripheral or central neurological deseases are providers of anorectal disorders of variable clinical expression (constipation, dyschezia, faecal incontinence (FI)…). Anorectal manometry (ARM) participates in their exploration to determine the underlying mechanisms, guide and optimize treatments. The objective of this work was to determine if there is a pattern of ARM data in neurological populations.

MATERIALS ET METHODS

Literature review from PubMed, Cochrane and Google scholar databases, using the following keywords: parkinsonian disorders; parkinson's disease; multiple slcerosis; neurolog*; spinal cord injury; spina bifida occulta; stroke; pudendal; endometriosis; peripheral nervous system diseases. 196 articles were isolated and finally 45 retained after reading the title and the abstract.

RESULTS

Data comparison was difficult due to the heterogeneity of techniques and thresholds used. In central lesions, resting and squeeze anal pressures were often altered. The presence of FI or constipation, the sex and the lesion level were factors influencing these data (low if complete injury, women or EDSS>5.5). In case of peripheral lesion, it is the anal tone and the contraction that varied the symptomatology. The sensory thresholds were variable regardless of the impairment.

CONCLUSION

This review did not identify a data pattern of ARM in central and peripheral neurological deseases. Gradual standardization of techniques and protocols will allow better comparison of data.

Faecal incontinence in adults

Faecal incontinence, which is defined by the unintentional loss of solid or liquid stool, has a worldwide prevalence of ≤7% in community-dwelling adults and can markedly impair quality of life. Nonetheless, many patients might not volunteer the symptom owing to embarrassment. Bowel disturbances, particularly diarrhoea, anal sphincter trauma (obstetrical injury or previous surgery), rectal urgency and burden of chronic illness are the main risk factors for faecal incontinence; others include neurological disorders, inflammatory bowel disease and pelvic floor anatomical disturbances. Faecal incontinence is classified by its type (urge, passive or combined), aetiology (anorectal disturbance, bowel symptoms or both) and severity, which is derived from the frequency, volume, consistency and nature (urge or passive) of stool leakage. Guided by the clinical features, diagnostic tests and therapies are implemented stepwise. When simple measures (for example, bowel modifiers such as fibre supplements, laxatives and anti-diarrhoeal agents) fail, anorectal manometry and other tests (endoanal imaging, defecography, rectal compliance and sensation, and anal neurophysiological tests) are performed as necessary. Non-surgical options (diet and lifestyle modification, behavioural measures, including biofeedback therapy, pharmacotherapy for constipation or diarrhoea, and anal or vaginal barrier devices) are often effective, especially in patients with mild faecal incontinence. Thereafter, perianal bulking agents, sacral neuromodulation and other surgeries may be considered when necessary.

The anorectal defaecation reflex: a prospective intervention study

AIM

Our hypothesis is that there may be a neural pathway with sensory afferent neurons in the anal canal that leads to rectal contraction to assist defaecation. We aimed to compare rectal motility between healthy participants with or without anal anaesthesia.

METHOD

This prospective intervention study consisted of two test sessions: a baseline session followed by an identical second session. During each session we performed the anal electrosensitivity test, the rectoanal inhibitory reflex test and rapid phasic barostat distensions. Prior to the second session, participants were randomly assigned to receive either a local anal anaesthetic or a placebo.

RESULTS

We included 23 healthy participants aged 21.1 ± 0.5 years, 13 of whom received an anal anaesthetic and 10 a placebo. All participants showed a transient rectal contraction during the first test session, which decreased significantly after anal anaesthesia (18.6 ml vs. 4.9 ml, p = 0.019). The maximum rectal contraction was comparable to the baseline results in the placebo group. Furthermore, the electrosensitivity at the highest centimetre of the anal canal correlated with the maximum rectal contraction (r = -0.452, p = 0.045).

CONCLUSION

All healthy study participants display an involuntary, reproducible rectal reflex contraction that appears to be innervated by afferent nerves in the proximal anal canal. The rectal reflex contraction appears to play a role in defaecation and we therefore refer to this phenomenon as the anorectal defaecation reflex. Knowledge of the anorectal defaecation reflex may have consequences for the diagnostics and treatment of constipation.

Altered epithelial barrier functions in the colon of patients with spina bifida

Our objectives were to better characterize the colorectal function of patients with Spina Bifida (SB). Patients with SB and healthy volunteers (HVs) completed prospectively a standardized questionnaire, clinical evaluation, rectal barostat, colonoscopy with biopsies and faecal collection. The data from 36 adults with SB (age: 38.8 [34.1-47.2]) were compared with those of 16 HVs (age: 39.0 [31.0-46.5]). Compared to HVs, rectal compliance was lower in patients with SB (p = 0.01), whereas rectal tone was higher (p = 0.0015). Ex vivo paracellular permeability was increased in patients with SB (p = 0.0008) and inversely correlated with rectal compliance (r = - 0.563, p = 0.002). The expression of key tight junction proteins and inflammatory markers was comparable between SB and HVs, except for an increase in Claudin-1 immunoreactivity (p = 0.04) in SB compared to HVs. TGFβ1 and GDNF mRNAs were expressed at higher levels in patients with SB (p = 0.02 and p = 0.008). The levels of acetate, propionate and butyrate in faecal samples were reduced (p = 0.04, p = 0.01, and p = 0.02, respectively). Our findings provide evidence that anorectal and epithelial functions are altered in patients with SB. The alterations in these key functions might represent new therapeutic targets, in particular using microbiota-derived approaches.Clinical Trials: NCT02440984 and NCT03054415.

Defecation induced by stimulation of sacral S2 spinal root in cats

The aim of this study was to determine whether stimulation of sacral spinal nerve roots can induce defecation in cats. In anesthetized cats, bipolar hook electrodes were placed on the S1-S3 dorsal and/or ventral roots. Stimulus pulses (1-50 Hz, 0.2 ms) were applied to an individual S1-S3 root to induce proximal/distal colon contractions and defecation. Balloon catheters were inserted into the proximal and distal colon to measure contraction pressure. Glass marbles were inserted into the rectum to demonstrate defecation by videotaping the elimination of marbles. Stimulation of the S2 ventral root at 7 Hz induced significantly (P < 0.05) larger contractions (32 ± 9 cmH₂O) in both proximal and distal colon than stimulation of the S1 or S3 ventral root. Intermittent (5 times) stimulation (1 min on and 1 min off) of both dorsal and ventral S2 roots at 7 Hz produced reproducible colon contractions without fatigue, whereas continuous stimulation of 5-min duration caused significant fatigue in colon contractions. Stimulation (7 Hz) of both dorsal and ventral S2 roots together successfully induced defecation that eliminated 1 or 2 marbles from the rectum. This study indicates the possibility to develop a novel neuromodulation device to restore defecation function after spinal cord injury using a minimally invasive surgical approach to insert a lead electrode via the sacral foramen to stimulate a sacral spinal root.NEW & NOTEWORTHY This study in cats determined the optimal stimulation parameters and the spinal segment for sacral spinal root stimulation to induce colon contraction. The results have significant implications for design of a novel neuromodulation device to restore defecation function after spinal cord injury (SCI) and for optimizing sacral neuromodulation parameters to treat non-SCI people with chronic constipation.

Neurogenic bowel dysfunction score in spinal cord-injured patients: translation and validation of the Dutch-language NBD score

STUDY DESIGN

This is a prospective validation study.

OBJECTIVES

The neurogenic bowel dysfunction (NBD) score is a widely used symptom-based questionnaire evaluating bowel dysfunction and its impact on quality of life (QoL) in spinal cord-injured patients. This study aimed to translate and validate a Dutch-language NBD score in patients with SCI.

SETTING

Patients with SCI visiting the urology department or general practitioner (GP) in Rotterdam, the Netherlands.

METHODS

Standardized guidelines were followed for the translation and validation process of the NBD score. Adult patients with SCI visiting our urology department were asked to participate by filling in a set of questionnaires: the NBD score, the Fecal Incontinence Quality of Life scale (FIQL), the Fecal Incontinence Severity Index (FISI), and the European Quality of life 5-Dimension 3-Level questionnaire (EQ-5D-3L) at baseline and 1-2 weeks afterward. A control group recruited at a GP office completed the questionnaires once. The following measurement properties were evaluated: content validity, internal consistency, reproducibility, criterion-, and construct validity.

RESULTS

Fifty-eight patients and 50 references were included. Content validity was adequate, internal consistency was moderate (Cronbach's alpha 0.56 and 0.30) and reproducibility was adequate (ICC 0.87). Criterion validity was confirmed; NBD score correlated significantly with the FIQL, FISI, and EQ-5D-3L. NBD scores in the patient group were significantly higher than in references, demonstrating good construct validity.

CONCLUSIONS

The Dutch-language version of the NBD score showed moderate to good measurement properties, and therefore is a reliable tool to measure bowel dysfunction in patients with SCI. We recommend standardized usage of this questionnaire for clinical evaluation and research purposes.

Chronic constipation in adults: Contemporary perspectives and clinical challenges. 1: Epidemiology, diagnosis, clinical associations, pathophysiology and investigation

BACKGROUND

Chronic constipation is a prevalent disorder that affects patients' quality of life and consumes resources in healthcare systems worldwide. In clinical practice, it is still considered a challenge as clinicians frequently are unsure as to which treatments to use and when. Over a decade ago, a Neurogastroenterology & Motility journal supplement devoted to the investigation and management of constipation was published (2009; 21 (Suppl.2)). This included seven articles, disseminating all themes covered during a preceding 2-day meeting held in London, entitled "Current perspectives in chronic constipation: a scientific and clinical symposium." In October 2018, the 3rd London Masterclass, entitled "Contemporary management of constipation" was held, again over 2 days. All faculty members were invited to author two new review articles, which represent a collective synthesis of talks presented and discussions held during this meeting.

PURPOSE

This article represents the first of these reviews, addressing epidemiology, diagnosis, clinical associations, pathophysiology, and investigation. Clearly, not all aspects of the condition can be covered in adequate detail; hence, there is a focus on particular "hot topics" and themes that are of contemporary interest. The second review addresses management of chronic constipation, covering behavioral, conservative, medical, and surgical therapies.

Recommendations for evaluation of neurogenic bladder and bowel dysfunction after spinal cord injury and/or disease

Objective: To provide an overview of clinical assessments and diagnostic tools, self-report measures (SRMs) and data sets used in neurogenic bladder and bowel (NBB) dysfunction and recommendations for their use with persons with spinal cord injury /disease (SCI/D).Methods: Experts in SCI/D conducted literature reviews, compiled a list of NBB related assessments and measures, reviewed their psychometric properties, discussed their use in SCI/D and issued recommendations for the National Institutes of Health (NIH), National Institute of Neurological Disorders and Stroke (NINDS) Common Data Elements (CDEs) guidelines.Results: Clinical assessments included 15 objective tests and diagnostic tools for neurogenic bladder and 12 for neurogenic bowel. Following a two-phase evaluation, eight SRMs were selected for final review with the Qualiveen and Short-Form (SF) Qualiveen and the Neurogenic Bowel Dysfunction Score (NBDS) being recommended as supplemental, highly-recommended due to their strong psychometrics and extensive use in SCI/D. Two datasets and other SRM measures were recommended as supplemental.Conclusion: There is no one single measure that can be used to assess NBB dysfunction across all clinical research studies. Clinical and diagnostic tools are here recommended based on specific medical needs of the person with SCI/D. Following the CDE for SCI studies guidelines, we recommend both the SF-Qualiveen for bladder and the NBDS for bowel as relatively short measures with strong psychometrics. Other measures are also recommended. A combination of assessment tools (objective and subjective) to be used jointly across the spectrum of care seems critical to best capture changes related to NBB and develop better treatments.

International standards to document remaining autonomic Function in persons with SCI and neurogenic bowel dysfunction: Illustrative cases

INTRODUCTION

Neurogenic bowel dysfunction (NBD) is a highly prevalent problem after spinal cord injury, with potential for significant impact on health and quality of life. The international standards to document remaining autonomic function after SCI were developed to standardize communication between professionals regarding neurogenic bowel and other autonomic function after SCI. To improve understanding of the bowel subsection, illustrative cases are presented.

CASE PRESENTATION

Three cases are presented which illustrate differences in presentation and scoring of the elements in the data set based upon varying injury severity and location.

DISCUSSION

Determination of neurologic level of injury is insufficient for assessment of autonomic function and there is no direct method of assessment. Hence, surrogate makers are needed. The bowel subsection of the International standards to document remaining autonomic function in persons with SCI is an easy-to-use tool for this purpose.

Altered Colorectal Compliance and Anorectal Physiology in Upper and Lower Motor Neurone Spinal Injury May Explain Bowel Symptom Pattern

OBJECTIVES

Supraconal spinal cord injury (SCI) and lower motor neurone spinal cord injury (LMN-SCI) cause bowel dysfunction; colorectal compliance may further define its pathophysiology. The aim of this study was to investigate rectal (RC) and sigmoid (SC) compliance and anorectal physiology parameters, in these subjects.

METHODS

Twenty-four SCI subjects with gut symptoms (14 RC, 10 SC) and 13 LMN-SCI subjects (9 RC, 4 SC) were compared with 20 spinal intact controls (10 RC, 10 SC). Staircase distensions were performed using a barostat. Anorectal manometry, including rectoanal inhibitory reflex (RAIR) measurement, was performed in all. Data presented as mean±standard error (SCI/LMN-SCI vs. controls).

RESULTS

SCI subjects had a higher RC (17.0±1.9 vs. 10.7±0.5 ml/mm Hg, P<0.05) and SC (8.5±0.6 vs. 5.2±0.5 ml/mm Hg, P=0.002). LMN-SCI subjects had a lower RC (7.3±0.7 ml/mm Hg, P=0.0021) while SC was unchanged (8.3±2.2 ml/mm Hg, P>0.05). Anal resting pressure was decreased in SCI (55±5 vs. 79±7 cmH2O, P=0.0102). Anal squeeze pressure was decreased in LMN-SCI (76±13 vs. 154±21 cmH2O, P=0.0158). In SCI and LMN-SCI, the amplitude reduction of the RAIR was greater (62±4% and 70±6% vs. 44±3%, P=0.0007).

CONCLUSIONS

Colorectal compliance abnormalities may explain gut symptoms: increased RC and SC contributing to constipation in SCI, reduced rectal compliance contributing to fecal incontinence (FI) in LMN-SCI. Reduced resting anal pressure in SCI and reduced anal squeeze pressure in LMN-SCI along with a greater RAIR amplitude reduction may be factors in FI. These co-existing abnormalities may explain symptom overlap, and represent future therapeutic targets to ameliorate neurogenic bowel dysfunction.

S1 nerve is the most efficient nerve rootlet innervating the anal canal and rectum in rats

Autonomic and somatic components participate in the defecation process in mammals, combining signals from the brainstem and forebrain. The innervation pattern involved in micturition in rats has been well studied, while defecation has been less studied. The aim of the present study was to identify the most important sensory and motor nerves of the anal canal and rectum involved in defecation. The amplitudes of evoked potential of the anal canal and rectum were higher when L6 and S1 ventral rootlets were stimulated, compared with the other segments (ANOVA and Tukey's post hoc test, all P < 0.05). The S1 segment was more strongly cholera toxin subunit B conjugated to horseradish peroxidase (CB-HRP) positive compared with the other segments (ANOVA and Tukey's post hoc test, P < 0.05). Ventral spinal rootlets of L6 and S1 mainly contributed to the pressure change in the anal canal and rectum when the ventral spinal rootlets from L5 to S3 were stimulated electrically. In conclusion, many afferent and efferent nerves innervate the anal canal and rectum and are involved in defecation, but the S1 nerve rootlet could be the most efficient one. These results could provide a basis for defecation reconstruction, especially for patients with spinal cord injuries.

Acute effect of electrical stimulation of the dorsal genital nerve on rectal capacity in patients with spinal cord injury

BACKGROUND

Constipation and fecal incontinence are considerable problems for most individuals with spinal cord injury (SCI). Neurogenic bowel symptoms are caused by several factors including abnormal rectal wall properties. Stimulation of the dorsal genital nerve (DGN) can inhibit bladder contractions and because of common innervation inhibitory effects are anticipated in the rectum too. Therefore, DNG could have a future role in the treatment of neurogenic fecal incontinence.

AIM

To study the effect of acute DGN stimulation on the rectal cross sectional area (CSA) in SCI patients.

METHODS

Seven patients with complete supraconal SCI (median age 50 years) were included. Stimulation was applied via plaster-electrodes using an amplitude of twice the genito-anal reflex threshold (pulse width: 200 μs; pulse rate: 20 Hz). A pressure controlled phasic (10, 20 and 30 cmH(2)O) rectal distension protocol was repeated four times with subjects randomized to stimulation during 1st and 3rd distension series or 2nd and 4th distension series. The rectal CSA and pressure were measured using impedance planimetry and manometry.

RESULTS

All patients completed the investigation. Median stimulation amplitude was 51 mA (range 30-64). CSA was smaller during stimulation and differences reached statistical significance at distension pressures of 20 cmH(2)O (average decrease 9%; P = 0.02) and 30 cmH(2)O (average decrease 4%; P = 0.03) above resting rectal pressure. Accordingly, rectal pressure-CSA relation was significantly reduced during stimulation at 20 (P=0.03) and 30 cmH(2)O distension (P=0.02).

CONCLUSION

DGN Stimulation in patients with supraconal SCI results in an acute decrease of rectal CSA and the rectal pressure-CSA relation.

The International Standards for Neurological Classification of Spinal Cord Injury: relationship between S4-5 dermatome testing and anorectal testing

STUDY DESIGN

Prospective cross-sectional multicenter study.

OBJECTIVE

To evaluate the correlation, sensitivity, specificity and predictive values of S4-5 dermatome and the anorectal examination for determination of sacral sparing in the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) examination.

SETTING

Two tertiary hospitals that specialize in pediatric spinal cord injuries.

METHODS

In all, 189 patients who were at minimum 3 month after spinal cord injury participated in complete ISNCSCI examinations. All examiners completed training for the proper completion of the ISNCSCI examination. Correlations and sensitivity/specificity analyses were conducted between S4-5 dermatome testing and the anorectal examination. Results were analyzed by age of patient, examiner, tetraplegia/paraplegia classification and injury level (T10-S3, L1-S3 and S3).

RESULTS

The correlation between S4-5 dermatome and anorectal sensation was moderate (0.62, P<0.001). Using the anorectal examination as the gold standard, the sensitivity of S4-5 testing was 0.60 (0.49, 70) and specificity was 0.96 (0.90, 0.99). No single age group, tester, level, or type of injury differed from the overall result.

CONCLUSION

In the pediatric population, the correlation between S4-5 and anorectal sensation was lower than anticipated. The sensitivity of 0.62 for S4-5 testing and diminished sensation between T10 and S3 suggests that anorectal testing may either be a more sensitive representation of S4-5 function or activate an alternative neuronal pathway that is perceived by the patient. Further investigation into the validity of the sacral sparing components of the ISNCSCI examination is warranted.

Neuroanatomy and physiology of colorectal function and defaecation: from basic science to human clinical studies

Colorectal physiology is complex and involves programmed, coordinated interaction between muscular and neuronal elements. Whilst a detailed understanding remains elusive, novel information has emerged from recent basic science and human clinical studies concerning normal sensorimotor mechanisms and the organization and function of the key elements involved in the control of motility. This chapter summarizes these observations to provide a contemporary review of the neuroanatomy and physiology of colorectal function and defaecation.

Discriminative value of anorectal manometry in clinical practice

Guidelines recommend anorectal manometry in patients with fecal incontinence and chronic constipation. However, limited evidence supports the utility of manometric testing. We retrospectively reviewed tracings obtained between November 2005 and May 2008. A total of 298 patients (86% women; average age 52 years) were included. The main indications were incontinence (51%) and constipation (42%). Patients suffering from incontinence were older and had lower resting and squeeze pressure compared to continent patients. However, the discriminative power of manometric pressure data was poor, with low sensitivity and specificity. An abnormal straining pattern suggesting dyssynergic defecation was seen in 43% of constipated patients compared to 13% of patients with fecal incontinence. A concordance between manometric patterns and the balloon expulsion test was seen in 72%. The low sensitivity and specificity of manometric parameters does not support the routine use of anorectal manometry in patients with defecation disorders.

Pathophysiology of bowel dysfunction in patients with motor incomplete spinal cord injury: comparison with patients with motor complete spinal cord injury

PURPOSE

Bowel dysfunction is a major problem in patients with spinal cord injury. Previous work has provided partial information, particularly about motor incomplete lesions. The purposes of this study were to evaluate the pathophysiologic features of neurogenic bowel in patients with motor incomplete spinal cord injury and to compare them with those in patients with motor complete lesions.

METHODS

Fifty-four patients (59% men; mean age, 43 years) with chronic spinal cord injury and fecal incontinence and/or constipation were evaluated; 32 had motor incomplete lesions, and 22 had motor complete lesions. Clinical assessment, colonic transit time, and anorectal manometry were performed.

RESULTS

Colonic transit time was delayed similarly in patients with motor complete lesions and those with motor incomplete lesions. Anal squeeze pressure was present in most patients with motor incomplete lesions and absent in all patients with motor complete lesions. The cough-anal reflex was less frequent in patients with motor complete lesions with a neurologic level above T7 (P < 0.05). Rectal sensitivity was less severely impaired in those with motor incomplete lesions (P < 0.05). Most patients in both groups did not show anal relaxation during defecatory maneuvers. Rectal contractions and anal sphincter activity during distention of the rectum were detected more often in patients with motor complete lesions (P < 0.05).

CONCLUSION

Many severe pathophysiologic mechanisms are involved in neurogenic bowel, affecting patients with motor incomplete spinal cord injury similarly to those of patients with motor complete lesions with spinal sacral reflexes. The pathophysiologic mechanisms of constipation are obstructed defecation, weak abdominal muscles, impaired rectal sensation, and delayed colonic transit time; the mechanisms of fecal incontinence are impaired external anal sphincter contraction, uninhibited rectal contractions, and impaired rectal sensation. However, specific evaluation is required in individual cases.

Neurogenic bowel dysfunction: pathophysiology, clinical manifestations and treatment

Bowel dysfunction (e.g., fecal incontinence, infrequent or difficult defecation) are both frequent and severely troubling problems for patients with spinal cord injury, multiple sclerosis and Parkinson's disease. The etiology of these symptoms is complex; there may be autonomic and pelvic nerve dysfunction (with attenuation of voluntary motor function and impaired anorectal sensation and anorectal reflexes), or generalized systemic factors (e.g., altered diet and behavior, impaired mobility, psychological disturbances or drug adverse effects). The mainstay of current treatment is adapting a conservative approach towards reversing the systemic effects and optimizing the mechanics of defecation through the use of laxatives and irrigation approaches. When successful, this approach improves both evacuation and incontinence symptoms, with associated improvements in quality of life and independence. Future therapies may be directed at modulating pelvic innervation through electrical stimulation. Stoma formation remains an option for patients refractory to other approaches.

Neurogenic colorectal and pelvic floor dysfunction

Constipation and faecal incontinence are common symptoms among patients with spinal cord injury (SCI), myelomeningocoele (MMC), multiple sclerosis (MS), Parkinson's disease (PD) and stroke. Faecal incontinence in SCI, MMC and MS is mainly due to abnormal rectosigmoid compliance and rectoanal reflexes, loss of rectoanal sensibility and loss of voluntary control of the external anal sphincter. Constipation in SCI, MMC and MS is probably due to immobilisation, abnormal colonic contractility, tone and rectoanal reflexes or side effects from medication. In PD, dystonia of the external anal sphincter causes difficult rectal evacuation and the loss of dopaminergic neurons in the enteric nervous system probably causes slow-transit constipation. Changes after stroke remain to be studied. Though dietary adjustments, oral laxatives, suppositories and other conservative treatment modalities are commonly used, evidence for their use in patients with central neurological disorders is scarce. For patients with severe symptoms trans-anal irrigation, the Malone appendicostomy or a colostomy can be recommended.

Effect of sacral anterior root stimulator on bowel dysfunction in patients with spinal cord injury

PURPOSE

Bowel dysfunction is a problem in patients with spinal cord injury. The sacral anterior root stimulator has been used for neurogenic bladder and has been claimed to be useful for neurogenic bowel. The purposes of this study were to analyze the clinical response of bowel function to the sacral anterior root stimulator and to evaluate physiologic factors that could determine its efficacy.

METHODS

Eighteen consecutive patients with spinal cord injury and an implanted sacral anterior root stimulator were evaluated. Clinical assessment, colonic transit time, and anorectal manometry were performed. Patients were evaluated before implantation of the sacral anterior root stimulator and clinically reevaluated after 12 months.

RESULTS

Fewer patients required laxatives after implantation of the sacral anterior root stimulator. The mean number of methods used to evacuate was reduced from 2.1 to 1.5 (P < 0.05). Bowel movement frequency was higher (P < 0.05). Time devoted to defecation was reduced, although no statistical significance was achieved. Fecal incontinence did not change, but constipation was reduced (P < 0.05). Most patients reported being more satisfied with bowel function after implantation of the sacral anterior root stimulator. No correlation was found between objective and subjective responses to the sacral anterior root stimulator and manometric or colonic transit times before implantation.

CONCLUSION

The sacral anterior root stimulator improves bowel function, and patient satisfaction with this treatment is high. Further studies are needed to evaluate the characteristics of stimulation parameters to achieve better results.

Neurophysiological testing in anorectal disorders

Neurophysiological tests of anorectal function can provide useful information regarding the integrity of neuronal innervation, as well as neuromuscular function. This information can give insights regarding the pathophysiological mechanisms that lead to several disorders of anorectal function, particularly fecal incontinence, pelvic floor disorders and dyssynergic defecation. Currently, several tests are available for the neurophysiological evaluation of anorectal function. These tests are mostly performed on patients referred to tertiary care centers, either following negative evaluations or when there is lack of response to conventional therapy. Judicious use of these tests can reveal significant and new understanding of the underlying mechanism(s) that could pave the way for better management of these disorders. In addition, these techniques are complementary to other modalities of investigation, such as pelvic floor imaging. The most commonly performed neurophysiological tests, along with their indications and clinical utility are discussed. Several novel techniques are evolving that may reveal new information on brain-gut interactions.

Cortical processing of residual ano-rectal sensation in patients with spinal cord injury: an fMRI study

Eleven paraplegic patients with complete traumatic spinal cord injuries (SCI) [according to American Spinal Injury Association (ASIA) criteria] at different levels (Th3-L3) were investigated during non-painful stimulation of the distal rectum and anal canal, using event related functional magnetic resonance imaging. Although a complete lesion was clinically diagnosed in all, four of them experienced reproducible sensations during anal and/or rectal stimulation. In six patients, individual data analysis revealed significant activation in the right secondary somatosensory cortex SII, the posterior cingular gyrus, the prefrontal cortex, and the left posterior cerebellar lobe during either anal or rectal stimulation or both. A Region of interest analysis using a data mask from healthy controls confirmed that SCI patients demonstrate cortical activation in areas similar to those activated in healthy volunteers, but to a less extensive degree. This supports the notion that the diagnosis of complete spinal cord transsection by ASIA criteria alone may be insufficient for assessment of 'completeness' of cord lesions, and that visceral sensitivity testing may be required in addition.

Alteraciones de la función intestinal en pacientes con lesión medular: relación con las características neurológicas de la lesión

BACKGROUND AND OBJECTIVE

The study consisted of a clinical evaluation of bowel dysfunction and the relation with neurological patterns in spinal cord injury (SCI).

PATIENTS AND METHOD

109 patients; 30% tetraplegics and 70% paraplegics; ASIA Impairment Scale: 65% A (complete), 12% B (sensitive incomplete), 11% C (motor incomplete with muscle grade <3), 13% D (motor incomplete with muscle grade >or= 3). 83% had spinal sacral reflexes (SSR). An interview and ano-rectal examination were performed.

RESULTS

77% patients required laxatives and 68% digital stimulation; 10% had bowel movements less than thrice a week and 18% spent more than one hour; 27% presented constipation, 31% fecal incontinence, 31% had ano-rectal pathology and 18% had autonomic dysreflexia (AD). Patients ASIA A,B,C with SSR took more suppositories, evacuated less frequently and spent more time than patients without SSR. Tetraplegics ASIA A,B,C had more constipation. Only patients with high level SCI and ASIA A,B,C with SSR had AD. ASIA D patients also needed laxatives, digital stimulation and presented colo-rectal symptoms.

CONCLUSIONS

The prevalence of colo-rectal symptoms is high in SCI patients and neurogenic bowel characteristics are related to neurological patterns.

Anorectal stimulation causes increased colonic motor activity in subjects with spinal cord injury

BACKGROUND

Difficulty with evacuation (DWE) is a major problem after spinal cord injury (SCI). Stimulation of the anal canal and lower rectum, accomplished using a gloved finger (so-called digital rectal stimulation or DRS) is often used as an adjunct to laxatives and enemas to facilitate bowel evacuation. However, the basis for the efficacy of DRS is not known. This study assessed the effect of DRS on colonic motility.

METHODS

Six subjects with SCI were studied several hours after a bowel care session. Colonic motility was assessed using a manometric catheter (affixed endoscopically to the splenic flexure) at baseline, during DRS, and after DRS. In addition, evacuation of barium oatmeal paste (with the consistency of stool and introduced into the rectum and descending colon) was assessed simultaneously using fluoroscopic techniques.

RESULTS

The mean number (+/- SEM) of peristaltic waves per minute increased from 0 at baseline to 1.9 (+/- 0.5/min) during DRS and 1.5 (+/- 0.3/min) during the period immediately after cessation of DRS (P < 0.05). The mean amplitude (+/- SEM) of the peristaltic contractions was 43.4 (+/- 2.2) mmHg. The frequency of contractions, as well as amplitude of contractions, during or immediately after DRS was not significantly different. These manometric changes in response to DRS were accompanied by expulsion of barium oatmeal paste in every subject by the fifth DRS.

CONCLUSIONS

DRS causes left-sided colonic activity in subjects with SCI. At least in part, an anorectal colonic reflex that results in enhanced contractions of the descending colon and rectum may contribute to bowel evacuation in individuals with SCI.

Bowel dysfunction in patients with motor complete spinal cord injury: clinical, neurological, and pathophysiological associations

BACKGROUND

Abnormal bowel function is a key problem in patients with spinal cord injury (SCI). Previous works provided only partial information on colonic transit time (CTT) or anal dysfunction but did not identified a comprehensive neurogenic bowel pattern.

AIM

To evaluate clinical, neurological, and pathophysiological counterparts of neurogenic bowel in patients with motor complete SCI.

METHODS

Fifty-four patients (56% men, mean age 35 yr) with chronic motor complete SCI (mean evolution time 6 yr) were evaluated: 41% with injuries above T7 (> T7) and 59% with injuries below T7 (< T7); patients were also classified according to the presence or not of sacral spinal reflexes. Clinical assessment, total and segmental CTT quantification, anorectal function evaluation by manometry, intrarectal balloon distension, and surface electromyography were performed.

RESULTS

Three different neuropathophysiological patterns were observed: Pattern A, present in > T7 injuries, characterized by very frequent constipation (86%) with significant defecatory difficulty and not very severe incontinence (Mean Wexner score 4.5); it was related to moderate delay in CTT (mainly in the left colon and recto-sigma), incapacity to increase the intra-abdominal pressure, and the absence of anal relaxation during the defecatory maneuvre; Pattern B, present in < T7 injuries with preserved sacral reflexes, characterized by not so frequent constipation (50%) but very significant defecatory difficulty and not very severe incontinence (Wexner 4.8); the pathophysiological counterpart was a moderate delay in CTT, capacity to increase intra-abdominal pressure, increased anal resistance during the defecatory maneuver, and presence of external anal sphincter (EAS) contraction when intra-abdominal pressure increased and during rectal distension; Pattern C, present in < T7 injuries without sacral reflexes, characterized by not very frequent constipation (56%) with less defecatory difficulty and greater severity of incontinence (Wexner 7.2); this was associated with severe delay in CTT (mainly in the left colon), capacity to increase intra-abdominal pressure, absence of anal resistance during the defecatory maneuver, and absence of EAS contraction when intra-abdominal pressure increased and during rectal distension.

CONCLUSION

In patients with motor complete SCI, we were able to define three different neuropathophysiological patterns that are associated with bowel function abnormalities and clinical complaints; this might be of help when designing therapeutic strategies.

Rectal hyposensitivity

Rectal hyposensitivity (RH) relates to a diminished perception of rectal distension that is diagnosed during anorectal physiologic investigation. There have been few direct studies of this physiologic abnormality, and its contribution to the development of functional bowel disorders has been relatively neglected. However, it appears to be common in patients with such disorders, being most prevalent in patients with functional constipation with or without fecal incontinence. Indeed, it may be important in the etiology of symptoms in certain patients, given that it is the only "apparent" identifiable abnormality on physiologic testing. Currently, it is usually diagnosed on the basis of elevated sensory threshold volumes during balloon distension in clinical practice, although such a diagnosis may be susceptible to misinterpretation in the presence of altered rectal wall properties, and thus it is uncertain whether a diagnosis of RH reflects true impairment of afferent nerve function. Furthermore, the etiology of RH is unclear, although there is limited evidence to support the role of pelvic nerve injury and abnormal toilet behavior. The optimum treatment of patients with RH is yet to be established. The majority are managed symptomatically, although "sensory-retraining biofeedback" appears to be the most effective treatment, at least in the short term, and is associated with objective improvement in the rectal sensory function. Currently, fundamental questions relating to the contribution of this physiologic abnormality to the development of functional bowel disorders remain unanswered. Acknowledgment of the potential importance of RH is thus required by clinicians and researchers to determine its relevance.

Mechanisms controlling normal defecation and the potential effects of spinal cord injury

Spinal cord injury frequently leads to bowel dysfunction with the result that emptying the bowel can occupy a significant part of the day and reduce the quality of life. This chapter contains an overview of the function and morphology of the normal distal gut in the human, and of gut behaviour in normal defecation. In humans, this can be monitored and is described, but knowledge of the mechanisms controlling it is limited. Work on animals has shown that the intrinsic activity of the smooth muscles and their interactions with the enteric nervous system can program the activity that is necessary to expel waste material, but the external anal sphincter is controlled through somatic nerves. The gut however also receives input from the central nervous system through autonomic nerves, and a spinal reflex centre exists. Voluntary effort to induce defecation can influence all the control mechanisms, but the precise importance of each is not understood. The behaviour and properties of the individual muscles in the normal human rectum and anal canal are described, including their responses to intrinsic nerve stimulation and adrenergic and cholinergic agonists. The effects of established spinal cord injury are then considered. For convenience, supraconal and conal/cauda equina lesions are considered as two categories. Prolongation of transit times and disordered defecation are common problems. Supraconal lesions result in reduced resting anal pressures and increased risk of fecal incontinence. The acute effects of spinal cord injury are described, with injury causing ileus (prolonged total gastrointestinal transit times), constipation (prolonged colonic transit times) and fecal incontinence (passive leakage).

Upper and lower gastrointestinal motor and sensory dysfunction after human spinal cord injury

This chapter describes the results of investigations of the upper and lower gastrointestinal tract in subjects with complete and incomplete spinal cord injury. In one study, gastric emptying was investigated and found delayed. The delay was tentatively attributed to a colo-gastric inhibitory reflex triggered by inappropriate colonic emptying. In another study, anorectal motor and sensory functions were measured. Decreased tone of the internal anal sphincter, exaggerated recto-anal reflexes following rectal distension and spontaneous high-amplitude rectal contractions at low distension volumes were among the findings of the study. Some of the subjects, classified as having a complete injury according to usual clinical criteria (American Spinal Injury Association, ASIA), reported sensation of distension of the rectum. This raises the issue of the need for better methods for the clinical assessment of sensory transmission in the spinal cord. Promising results obtained with functional magnetic resonance imaging of the brain during rectal stimulation in a small group of paraplegics, with complete injuries by ASIA criteria, showed evidence of activation of several brain regions.

Neurogenic bowel dysfunction score

STUDY DESIGN

Cross-sectional questionnaire study.

OBJECTIVES

To develop and validate a symptom-based score for neurogenic bowel dysfunction (NBD): NBD score.

SETTING

University Hospital of Aarhus, Denmark.

METHODS

A questionnaire including questions about background parameters (n=8), faecal incontinence (n=10), constipation (n=10), obstructed defecation (n=8), and impact on quality of life (QOL) (n=3) was sent to 589 Danish spinal cord injured (SCI) patients. The reproducibility and validity of each item was tested in 20 and 18 patients, respectively. Associations between items and impact on QOL were determined by logistic regression analysis. The NBD score was constructed from items with acceptable reproducibility and validity that were significantly associated with impact on QOL. Based on odds ratios for associations between items and impact on QOL, each item was given a corresponding number of points in the NBD score.

RESULTS

A total of 424 SCI patients responded. The following 10 items met the criteria above: frequency of bowel movements (0-6 points), headache, perspiration or discomfort before or during defecation (0-2 points), tablets and drops against constipation (0-2 points each), time used for each defecation (0-7 points), frequency of digital stimulation or evacuation (0-6 points), frequency of faecal incontinence (0-13 points), medication against faecal incontinence (0-4 points), flatus incontinence (0-2 points) and perianal skin problems (0-3 points). Differences in NBD score among patients reporting no, little, some or major impact on QOL were statistically significant (all P<0.001).

CONCLUSION

Based on valid and reproducible questions, we have constructed a score for NBD that is correlated to impact on QOL.

Effect of sacral neuromodulation on the rectum

Background

Sacral neuromodulation (SNM) is a new treatment for faecal incontinence. At present the exact underlying mechanism is still unclear. Modulation of the sacral reflex arcs might have an effect on rectal sensitivity, wall tension and compliance.

Methods

Fifteen consecutive patients with faecal incontinence who qualified for SNM underwent barostat measurements before and during neuromodulation. An ‘infinitely’ compliant plastic bag with a volume of 600 ml was placed in the rectum and connected to a computer-controlled barostat system. An isobaric phasic distension protocol was used. Patients were asked to report rectal filling sensations: first sensation (FS), earliest urge to defaecate (EUD) and an irresistible, painful urge to defaecate (maximum tolerated volume; MTV). Rectal wall tension and compliance were calculated.

Results

During isobaric phasic distension each patient experienced all rectal filling sensations at the time of stimulation. Median volume thresholds decreased significantly during stimulation, from 98·1 to 44·2 ml for FS (P = 0·003), from 132·3 to 82·8 ml for EUD (P = 0·001) and from 205·8 to 162·8 ml for MTV (P = 0·002). Pressure thresholds tended to be lower for all filling sensations, but only that to evoke MTV was reduced significantly by stimulation (37·3 versus 30·3 mmHg; P = 0·005). Median rectal wall tension for all filling sensations decreased significantly with stimulation. There was no significant difference between compliance before and during stimulation.

Conclusion

SNM affects rectal sensory perception, but further research is required to clarify the mechanism.

[Assessment of anorectal disorders with paraplegia]

INTRODUCTION

Functional anorectal disorders in paraplegia are frequent; few studies evaluate the effect of these disorders on quality of life.

OBJECTIVE

Assessment of the functional anorectal disorders in a homogeneous group of patients with total paraplegia in terms of quality of life.

METHODS

During a global follow-up consultation, patients answered questions on a systematic questionnaire about anorectal disorders and a specific quality-of-life autoquestionnaire about functional digestive disorders: Functional Digestive Disorders Quality of Life (FDDQL) questionnaire; score 0 to 100 (100 corresponding to no effect on quality of life).

RESULTS

Twenty-three patients with a mean age of 44.3 years who had been paraplegic for 10 years participated. Two had a colostomy because of bedsores. Fourteen underwent daily rectal examination, 10 with an evacuation aim; the time given to defecation was, on average, 36 minutes. One patient had clinical constipation. Twelve had had one or more episodes of incontinence. The mean global FDDQL score was 69.7. This score was not related to incontinence; only the "comfort" domain among the 8 domains was related to incontinence.

DISCUSSION

Anorectal disorders are frequent in paraplegia; the duration and the methods of defecation represent a great worry to patients. More than half of the patients already had faecal incontinence; the effect of even occasional incontinence on quality of life is significant. Since the FDDQL scale is not specific to patients with paraplegia, its interest should be checked on a greater number of patients. For certain patients, it is important not to dismiss more complex surgical treatment methods.

Sacral anterior root stimulated defecation in spinal cord injuries: An experimental study in canine model

AIM: To investigate whether there was a dominant sacral root for the motive function of rectum and anal sphincter, and to provide an experimental basis for sacral root electrically stimulated defecation in spinal cord injuries.

METHODS: Eleven spinal cord injured mongrel dogs were included in the study. After L4-L7 laminectomy, the bilateral L7-S3 roots were electrostimulated separately and rectal and sphincter pressure were recorded synchronously. Four animals were implanted electrodes on bilateral S2 roots.

RESULTS: For rectal motorial innervation, S2 was the most dominant (mean 15.2 kPa, 37.7% of total pressure), S1 (11.3 kPa, 27.6%) and S3 (10.9 kPa, 26.7%) contributed to a smaller part. For external anal sphincter, S3 (mean 17.2 kPa, 33.7%) was the most dominant, S2 (16.2 kPa, 31.6%) and S1 (14.3 kPa, 27.9%) contributed to a lesser but still a significant part. Above 85% L7 roots provided some functional contribution to rectum and anal sphincter. For both rectum and sphincter, the right sacral roots provided more contribution than the left roots. Postoperatively, the 4 dogs had electrically stimulated defecation and micturition under the control of the neuroprosthetic device.

CONCLUSION: S2 root is the most dominant contributor to rectal pressure in dogs. Stimulation of bilateral S2 with implanted electrodes contributes to good micturition and defecation in dogs.

The anal reflex elicited by cough and sniff: validation of a neglected clinical sign

BACKGROUND

It is unclear whether contraction of the external anal sphincter (EAS) following a voluntary cough is an integral component of the cough response itself, or a reflex response to the abdominal and pelvic floor dynamics induced by the cough. Clinical experience suggests a reflex origin for this response.

OBJECTIVE

To compare motor latencies for intercostal, abdominal, and EAS muscle contraction after transcranial magnetic stimulation with those following voluntary coughing and sniffing.

METHODS

A needle electrode inserted into the EAS measured responses, which were confirmed by tonic electromyographic recording. Direct motor latencies from the cerebral cortex to the intercostal, rectus abdominis and EAS muscles were obtained using transcranial magnetic stimulation. Sniff and cough induced responses were also recorded in these muscles.

RESULTS

The results suggest that EAS responses following a voluntary cough or sniff represent a polysynaptic reflex.

CONCLUSIONS

As the cough induced anal reflex response is consistent and easily elicited, its use in clinical neurological examination is appropriate.

Review article: Recent trends in diagnosis and treatment of faecal incontinence

The inability to control bowel discharge is not only common but extremely distressing. It has a negative impact on a patient's lifestyle, leads to a loss of self-esteem, social isolation and a diminished quality of life. Faecal incontinence is often due to multiple pathogenic mechanisms and rarely due to a single factor. Normal continence to stool is maintained by the structural and functional integrity of the anorectal unit. Consequently, disruption of the normal anatomy or physiology of the anorectal unit leads to faecal incontinence. Currently, several diagnostic tests are available that can provide an insight regarding the pathophysiology of faecal incontinence and thereby guide management. The treatment of faecal incontinence includes medical, surgical or behavioural approaches. Today, by using logical approach to management, it is possible to improve symptoms and bowel function in many of these patients.

Colorectal transport during defecation in patients with lesions of the sacral spinal cord

Normal defecation involves reflexes between the colorectum and sacral spinal cord. Lesions of the conus medullaris or cauda equina interrupt such reflex arches and cause constipation. The aim of the study was to compare colorectal transport during defecation in patients with sacral spinal cord lesions and healthy volunteers. Ten patients with sacral spinal cord lesions (six men and four women, age 21-57 y, median = 36) and 16 healthy volunteers (10 men and six women, age 22-42 y, median = 30) took one or two doses of 111In-labelled polystyrene pellets perorally to mark colorectal contents. Abdominal scintigraphy was performed before and after defecation. Total colorectal emptying and segmental antegrade or retrograde transport was computed. Median colorectal emptying during normal defecation was 81% of the rectosigmoid (range: 53% of the rectosigmoid to complete emptying of the rectosigmoid and 40% of the descending colon) in healthy volunteers and 27% of the rectosigmoid (range: 0-44% of the rectosigmoid) in patients with conal/cauda equina lesions (P < 0.001). Median antegrade transport was 82% (control group) vs 27% (patients) of the rectosigmoid (P < 0.001), 38% vs 4% of the descending colon (P < 0.02), 13% vs 1% of the transverse colon (P = 0.28), and 4% vs 2% of the caecum/ascending colon (P = 0.76). It is concluded that damage to reflex arches between the colorectum and the sacral spinal cord significantly reduces emptying of the rectosigmoid and descending colon during defecation.

Influences of pelvic floor structures and sacral innervation on the response to distension of the cat rectum

The contributions to the rectal response to distension of the pelvic floor structures surrounding the rectum and of the sacral spinal innervation have never been studied. Using paralysed intercollicularly decerebrate, anaesthesia-free cats, we studied pressure-volume relationships during slow ramp distensions of the rectum. Results obtained from animals with intact pelvic cavities were compared with those following mobilization of the rectum from the pelvic floor musculature. To assess the influences of spinal outflow and afferent input, rectal pressure-volume relationships were measured in the mobilized rectum following bilateral sequential transection of the spinal roots S1 to S3, first dorsal, then ventral. Isolation of the rectum from the pelvic floor structures resulted in a decrease in balloon volume in the lower range of distension pressure but did not affect volumes at higher pressures. The only afferent effect was seen after sectioning of dorsal roots S1, which resulted in a decrease in balloon volume. The only efferent effect was seen after sectioning of ventral roots S3, which decreased balloon volume further. In conclusion, the rectal response to distension depends on the properties of the rectal wall. It may be influenced by somatic inputs, inputs from the myenteric nervous plexus, and from the parasympathetic and sympathetic nervous systems. Afferent inputs and spinal autonomic reflexes may decrease the tone of the rectal musculature during distension.

Neurogenic female sexual dysfunction: a review

The effect of various spinal lesions on female sexual response has recently been investigated in detail. Studies of women with neurologic disabilities and studies of animal models have provided substantial information regarding the spinal control of sexual responses. In this report, the authors explore findings regarding the neurologic pathways underlying the spinal control of sexual arousal and orgasm. Information available about the effects of multiple sclerosis and various cerebral disorders on female sexual function will also be reviewed, with special attention to areas where further research is needed. Lastly, the current status and techniques available to improve the sexual functioning of women with neurologic disabilities affecting the central nervous system will be reviewed.

Rectal sensory perception in females with obstructed defecation

PURPOSE

Parasympathetic afferent nerves are thought to mediate rectal filling sensations. The role of sympathetic afferent nerves in the mediation of these sensations is unclear. Sympathetic nerves have been reported to mediate nonspecific sensations in the pelvis or lower abdomen in patients with blocked parasympathetic afferent supply. It has been reported that the parasympathetic afferent nerves are stimulated by both slow ramp (cumulative) and fast phasic (intermittent) distention of the rectum, whereas the sympathetic afferent nerves are only stimulated by fast phasic distention. Therefore, it might be useful to use the two distention protocols to differentiate between a parasympathetic and sympathetic afferent deficit.

METHODS

Sixty control subjects (9 males; median age, 48 (range, 20-70) years) and 100 female patients (median age, 50 (range, 18-75) years) with obstructed defecation entered the study. Rectal sensory perception was assessed with an "infinitely" compliant polyethylene bag and a computer-controlled air-injection system. This bag was inserted into the rectum and inflated with air to selected pressure levels according to two different distention protocols (fast phasic and slow ramp). The distending pressures needed to evoke rectal filling sensations, first sensation of content in the rectum, and earliest urge to defecate were noted, as was the maximum tolerable volume.

RESULTS

In all control subjects, rectal filling sensations could be evoked. Twenty-one patients (21 percent) experienced no sensation at all in the pressure range between 0 and 65 mmHg during either slow ramp or fast phasic distention. The pressure thresholds for first sensation, earliest urge to defecate, and maximum tolerable volume were significantly higher in patients with obstructed defecation (P < 0.001). In each subject, the pressure thresholds for first sensation, earliest urge to defecate, and maximum tolerable volume were always the same, regardless of the type of distention.

CONCLUSION

Rectal sensory perception is blunted or absent in the majority of patients with obstructed defecation. The observation that this abnormality can be detected by both distention protocols suggests that the parasympathetic afferent nerves are deficient. Because none of the patients experienced a nonspecific sensation in the pelvis or lower abdomen during fast phasic distention, it might be suggested that the sympathetic afferents are also deficient. This finding implies that it is not worthwhile to use different distention protocols in patients with obstructed defecation.

Rectal compliance in females with obstructed defecation

PURPOSE

This study was designed to investigate whether rectal compliance is altered in females with obstructed defecation.

METHODS

Eighty female patients with obstructed defecation and 60 control subjects were studied. Rectal compliance was measured with an "infinitely compliant" polyethylene bag. This bag was inserted in the rectum and inflated with air to selected pressure plateaus (range, 0-60 mmHg; cumulative steps of 2 mmHg with a duration of ten seconds) using a computer-controlled electromechanical barostat system. Volume changes at the levels of distending pressures were recorded. The distending pressures, needed to evoke first sensation of content in the rectum, earliest urge to defecate, and the maximum tolerable volume were noted.

RESULTS

In all cases, the compliance curve had a characteristic triphasic (S-shaped) form. The mean compliance curve obtained from the patients was identical to that of the controls. However, the course of the compliance curve fell above the normal range (mean + 2 SD) in 14 patients. In ten (71 percent) of these patients, a large rectocele was seen at evacuation proctography. Such a rectocele was observed in only five patients (7.6 percent) with a normal compliance curve (P < 0.001). Eighty percent of the controls experienced earliest urge to defecate during the second phase of the curve. In 75 percent of the patients, this occurred in the third phase. The mean pressure threshold for first sensation, earliest urge to defecate, and maximum tolerable volume were significantly higher in patients compared with control subjects. Ten of the patients experienced no sensation at all in the pressure range between 0 and 60 mmHg.

CONCLUSION

In females with obstructed defecation, the compliance of the rectal wall is normal.

Neurologic disorders affecting the anorectum

Neurologic disorders that affect the brain, spinal cord, or extrinsic innervation may present with similar symptoms and share common pathophysiology, such as rectal impaction, loss of an urge to defecate, inability to trigger a defecation sequence, obstructive defecation, or incontinence. If these symptoms are persistent or bothersome, they require treatment. The management of a patient with neurologic anorectal dysfunction depends on the underlying pathophysiologic mechanisms. Dietary advice, bowel training, pharmacotherapy, and rehabilitative treatment may be used alone or in combination.

Manometric assessment of anorectal function

A diagnostic test is useful if it can provide information regarding the underlying pathophysiology, confirm a clinical suspicion, or guide clinical management. In a prospective study, anorectal manometry was shown not only to confirm a clinical impression, but also to provide new information that was not detected clinically. The information obtained from these studies influenced the management and outcome of patients with defecation disorders (Table 1). These findings have been confirmed further by another study that showed colorectal physiologic tests provided a definitive diagnosis in 75% of patients with constipation, 66% of patients with incontinence, and 42% of patients with intractable anorectal pain. A systematic and careful appraisal of anorectal function can provide invaluable information that can guide treatment of patients with anorectal disorders. A more uniform method of performing these tests and interpreting the results is needed to facilitate a wider use of this technology for the assessment of patients with anorectal disorders.

Sexual arousal and orgasm in women: effects of spinal cord injury

Sexual disorders are common in women; however, the neurological basis of female sexual response has not been adequately investigated. This information is necessary to characterize the impact of various neurological disorders on sexual arousal in women and to develop appropriate management strategies for sexual dysfunction. To assess the spinal mediation of sexually stimulated genital vasocongestion in women, we conducted two laboratory-based, controlled analyses: (1) of women's genital, subjective, and autonomic responses to audiovisual erotic and audiovisual erotic combined with manual genital stimulation; and (2) of women's ability to achieve orgasm. Subjects included 68 premenopausal women with spinal cord injuries (SCIs) and 21 able-bodied, age-matched controls. Results indicated that preservation of sensory function in the T11-L2 dermatomes is associated with psychogenically mediated genital vasocongestion. Less than 50% of women with SCIs were able to achieve orgasm, compared with 100% of able-bodied women (p = 0.001). Only 17% of women with complete lower motor neuron dysfunction affecting the S2-S5 spinal segments were able to achieve orgasm, compared with 59% of women with other levels and degrees of SCIs (p = 0.048). Time to orgasm was significantly increased in women with SCIs compared with able-bodied controls (p = 0.049). Independent raters were unable to differentiate between subjective descriptions of orgasm from SCI women compared with controls. This information should be used when counseling women with spinal dysfunction about their sexual potential.

Anorectal functions in patients with spinal cord injury

We wished to establish anorectal functions in patients with spinal cord lesions, related to the level of lesion and its completeness. We also wished to determine the value of neurophysiological tests for completeness of transsections in comparison with manometry and visceral sensory testing. In 32 patients (31.5 +/- 14.1 years, 25 males) with spinal trauma, completeness of transsection was assessed clinically. In 16 of these patients (30 +/- 15.6 years, nine males), a neurological work-up included recording of somatosensory evoked potentials (SEP) and motor evoked potentials (MEP) from the pudendal nerve within the first week after trauma. Also, anal sphincter EMG and pudendal nerve terminal motor latency (PNTML) were assessed. All patients also underwent conventional anorectal manometry and visceral sensory testing. Of all 32 patients, 15 were judged as 'complete' based on their clinical signs. Of those 16 tested neurologically, seven were labelled 'complete' since no MEP or SEP were detectable; one had pudendal SEP and MEP present, while SEP were present but delayed (47.0 +/- 8.8 msec) in the remaining patients. In four of these patients, also MEP were recorded (27.9 +/- 5.2 msec) and normal. PNTML was present in 12/16 patients independent of the completeness of lesion, and was rated normal in nine and delayed in three patients. EMG was normal in five, and pathological in 11 cases. In 5/15 cases of those judged as 'complete' (in 3/7 evaluated neurologically), visceral sensory testing revealed a minimal threshold for rectal perception of distension of 44 mL (range: 10-130), which sometimes was also perceived as urge to defecate. In a further case, manometry showed major voluntary action of the anal sphincter. These patients had lesions at all levels of the spinal column, ranging from cervical (C4,C6,C7) via thoratical (2 x T7,T8,T12) to lumbar segments. Anorectal function testing, and specifically visceral sensory testing may be superior to neurological assessment of 'completeness' of spinal cord lesions. It may be that visceral afferent pathways others than spinothalamic tract are involved in rectal perception that are less accessible to conventional neurophysiological diagnostic work-up.

Octreotide acts on anorectal physiology: a dynamic study in healthy subjects

BACKGROUND

Somatostatin is localized in the intestinal and pelvic nerves of the anorectum and it seems to act as an important neurotransmitter. However, previous analyses of octreotide (a somatostatin analog) effects on anal function showed conflicting results. By use of a dynamic model in healthy subjects, with comparison to the myogenic effect of glucagon, the aim of our study was to further investigate the pharmacologic targets of octreotide.

METHODS

This was a placebo-controlled, randomized, double-blinded crossover study performed in 12 healthy volunteers who received octreotide, glucagon, or placebo intravenously on separate days. During each sequence, several pressure steps in 3 different protocols of rectal isobaric distension were applied with an electronic barostat. Manometric responses of the anal canal, adaptative volumes, and perception scores of the rectum were recorded.

RESULTS

During both phasic and stepwise distensions, a significant drug effect was encountered at the anal level. Compared with placebo, octreotide significantly increased pressures at both upper and lower levels of the anal canal. In contrast, glucagon decreased pressures at the upper part of the anal canal. Octreotide significantly decreased rectal volumes to phasic distension, but glucagon did not induce any change on rectal adaptation. In addition, neither drug modified perception scores.

CONCLUSION

This study suggests that octreotide acts on reflex arcs and rectal myenteric neurons rather than on anal myogenic targets that respond to glucagon.

Sacral reflexes: physiology and clinical application

Sacral reflexes consist of motor responses in the pelvic floor and sphincter muscles evoked by stimulation of sensory receptors in pelvic skin, anus, rectum, or pelvic viscera. These responses may be elicited by physical or electrical stimuli. They have been used in research studies of the pathophysiology of pelvic floor and anorectal disorders and many have been recommended for diagnostic use. These reflexes are described and discussed in this review. More rigorous evaluation of their value in the clinical assessment and care of patients with pelvic floor and sphincter disorders is required. Currently direct comparisons of the value of particular responses are generally not available, and few of these reflexes have proven validity for use in clinical diagnosis.