Impaired anal sensation and early diabetic faecal incontinence

[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.

Understanding the physiology of human defaecation and disorders of continence and evacuation

The act of defaecation, although a ubiquitous human experience, requires the coordinated actions of the anorectum and colon, pelvic floor musculature, and the enteric, peripheral and central nervous systems. Defaecation is best appreciated through the description of four phases, which are, temporally and physiologically, reasonably discrete. However, given the complexity of this process, it is unsurprising that disorders of defaecation are both common and problematic; almost everyone will experience constipation at some time in their life and many will develop faecal incontinence. A detailed understanding of the normal physiology of defaecation and continence is critical to inform management of disorders of defaecation. During the past decade, there have been major advances in the investigative tools used to assess colonic and anorectal function. This Review details the current understanding of defaecation and continence. This includes an overview of the relevant anatomy and physiology, a description of the four phases of defaecation, and factors influencing defaecation (demographics, stool frequency/consistency, psychobehavioural factors, posture, circadian rhythm, dietary intake and medications). A summary of the known pathophysiology of defaecation disorders including constipation, faecal incontinence and irritable bowel syndrome is also included, as well as considerations for further research in this field.

Management of colorectal cancer and diabetes

Colorectal cancer is associated with diabetes mellitus and both of these common conditions are often managed together by a surgeon. The surgical focus is usually upon cancer treatment rather than diabetes management. The relationship between colorectal cancer and diabetes is a complex one and can raise problems in both diagnosis and the management of patients with both conditions. This literature review explores the relationship between diabetes, diabetic treatment and colorectal cancer and addresses the issues that arise in diagnosing and treating this patient group. By highlighting these difficulties, this review aims to improve understanding and to provide clearer insight into both surgical and non-surgical management.

Postpartum pelvic floor trauma

PURPOSE OF REVIEW

There is strong epidemiological evidence linking vaginal childbirth and the development of postpartum incontinence and prolapse. This article examines possible mechanisms of pelvic floor damage related to delivery and their possible consequences.

RECENT FINDINGS

Histology, imaging and physiology studies have revealed that vaginal delivery results in direct pelvic muscle trauma, disruption of fascial supports and pudendal nerve injury.

SUMMARY

Epidemiology studies implicate parity and childbirth in the development of incontinence and prolapse; however, despite imaging and functional studies revealing damage to the pelvic floor muscles, nerves and fascial supports, it is unclear what the clinical significance of these findings is. In addition, the effect of mode of delivery is uncertain, and although cesarean section reduces the risk of pelvic floor trauma, it is not entirely protective. Further research is required into the effect of pregnancy on pelvic floor dysfunction and the effect of mode of delivery.

Faecal incontinence in male patients

OBJECTIVE

Data concerning faecal incontinence (FI) in men are lacking. The aim of this study was to evaluate the historical aetiology and contrast aetiologies in younger and older men suffering from FI.

METHOD

After institutional review board approval, a retrospective chart review was undertaken of all patients with FI seen between 1999 and 2005. The data of male patients was further analysed to assess the impact of age and historical aetiology on FI.

RESULTS

A total of 404 males were included, 203 patients were <70 years of age (group A) and 201 patients were >or=70 years of age (group B). The most common prior diagnosis in group A was perianal sepsis in 23 (11.3%) patients and symptomatic haemorrhoids in 20 (9.9%) patients; in group B it was prostate cancer in 57 (28.4%) patients, symptomatic haemorrhoids in 31 (15.4%) patients and neurological diseases in 18 (9%) patients. The most common prior procedure in group A was restorative proctectomy/proctocolectomy in 32 (15.8%) patients, fistulotomy or haemorrhoidectomy in 21 (10.3%) and 19 (9.4%) patients respectively. In group B, radiation therapy for prostate cancer was utilized in 48 (23.9%) patients and haemorrhoidectomy in 29 (14.4%) patients. Comparing group A and group B relative to diagnosis - perianal sepsis, perineal trauma, congenital disorders, HIV infection and anal cancer were more common in group A, whereas prostate cancer, neurological diseases and colon cancer were significantly more common in group B.

CONCLUSION

Prostate cancer, symptomatic haemorrhoids, perianal sepsis, rectal cancer and a history of restorative rectal resection were common associations with FI in men. The aetiologies for FI in men vary with age.

Diabetes and the enteric nervous system

Diabetes is associated with several changes in gastrointestinal (GI) motility and associated symptoms such as nausea, bloating, abdominal pain, diarrhoea and constipation. The pathogenesis of altered GI functions in diabetes is multifactorial and the role of the enteric nervous system (ENS) in this respect has gained significant importance. In this review, we summarize the research carried out on diabetes-related changes in the ENS. Changes in the inhibitory and excitatory enteric neurons are described highlighting the role of loss of inhibitory neurons in early diabetic enteric neuropathy. The functional consequences of these neuronal changes result in altered gastric emptying, diarrhoea or constipation. Diabetes can also affect GI motility through changes in intestinal smooth muscle or alterations in extrinsic neuronal control. Hyperglycaemia and oxidative stress play an important role in the pathophysiology of these ENS changes. Antioxidants to prevent or treat diabetic GI motility problems have therapeutic potential. Recent research on the nerve-immune interactions demonstrates inflammation-associated neurodegeneration which can lead to motility related problems in diabetes.

Neurophysiological testing in anorectal disorders

The neurophysiological techniques currently available to evaluate anorectal disorders include concentric needle electromyography (EMG) of the external anal sphincter, anal nerve terminal motor latency (TML) measurement in response to transrectal electrical stimulation or sacral magnetic stimulation, motor evoked potentials (MEPs) of the anal sphincter to transcranial magnetic cortical stimulation, cortical recording of somatosensory evoked potentials (SEPs) to anal nerve stimulation, quantification of electrical or thermal sensory thresholds (QSTs) within the anal canal, sacral anal reflex (SAR) latency measurement in response to pudendal nerve or perianal stimulation, and perianal recording of sympathetic skin responses (SSRs). In most cases, a comprehensive approach using several tests is helpful for diagnosis: needle EMG signs of sphincter denervation or prolonged TML give evidence for anal motor nerve lesion; SEP/QST or SSR abnormalities can suggest sensory or autonomic neuropathy; and in the absence of peripheral nerve disorder, MEPs, SEPs, SSRs, and SARs can assist in demonstrating and localizing spinal or supraspinal disease. Such techniques are complementary to other methods of investigation, such as pelvic floor imaging and anorectal manometry, to establish the diagnosis and guide therapeutic management of neurogenic anorectal disorders.

Effects of acute hyperglycaemia on anorectal motor and sensory function in diabetes mellitus

AIMS

To determine the effects of acute hyperglycaemia on anorectal motor and sensory function in patients with diabetes mellitus.

METHODS

In eight patients with Type 1, and 10 patients with Type 2 diabetes anorectal motility and sensation were evaluated on separate days while the blood glucose concentration was stabilized at either 5 mmol/l or 12 mmol/l using a glucose clamp technique. Eight healthy subjects were studied under euglycaemic conditions. Anorectal motor and sensory function was evaluated using a sleeve/sidehole catheter, incorporating a barostat bag.

RESULTS

In diabetic subjects hyperglycaemia was associated with reductions in maximal (P<0.05) and plateau (P<0.05) anal squeeze pressures and the rectal pressure/volume relationship (compliance) during barostat distension (P<0.01). Hyperglycaemia had no effect on the perception of rectal distension. Apart from a reduction in rectal compliance (P<0.01) and a trend (P=0.06) for an increased number of spontaneous anal sphincter relaxations, there were no differences between the patients studied during euglycaemia when compared with healthy subjects.

CONCLUSIONS

In patients with diabetes, acute hyperglycaemia inhibits external anal sphincter function and decreases rectal compliance, potentially increasing the risk of faecal incontinence.

Colorectal symptoms in patients with neurological diseases

Several neurological diseases cause constipation or faecal incontinence restricting social activities and influencing quality of life. As several new treatment modalities have become available within the last few years, doctors treating patients with neurological diseases should be aware of the symptoms and have a basic knowledge of relevant treatment options. Constipation and faecal incontinence are common symptoms in patients with traumatic spinal cord injuries, spina bifida, multiple sclerosis, diabetic polyneuropathy, Parkinson's disease, stroke, and cerebral palsy. New treatment modalities are: prokinetic agents, enemas administered through the enema continence catheter or through an appendicostomy, and biofeed-back. Sacral nerve stimulation is still mostly at an experimental level and colostomy should be restricted to the few patients with most severe problems resistant to other therapy.

Impairment of anorectal function in diabetes mellitus parallels duration of disease

PURPOSE

The aim of this study was to investigate any possible relation between the severity of anorectal dysfunction in diabetes mellitus and duration of disease and presence of microangiopathy or neuropathy or both.

METHODS

Standard multiport anorectal manometry was performed in 25 healthy control subjects (10 males; age (mean +/- 1 standard deviation), 62 +/- 14 years) and 38 patients with diabetes mellitus. Patients were divided into two groups according to the duration of the disease: Group A (19 patients) with a duration less than 10 years (7.2 +/- 2.5; 8 males; age, 57 +/- 18) and Group B (19 patients) with a duration longer than 10 years (19.8 +/- 5.6; 6 males; age, 62 +/- 15).

RESULTS

Results are reported as mean +/- one standard deviation. Patients showed lower resting and squeeze anal pressures (P < 0.01), impaired rectoanal inhibitory and anocutaneous reflexes, and reduced sensitivity in rectal distention (P = 0.004) as compared with controls. In addition, Group B showed a significantly increased incidence of microangiopathy (P = 0.04) and autonomic and peripheral neuropathy (P = 0.002), significantly reduced basal and squeeze anal pressures (52 +/- 16 vs. 64 +/- 24 mmHg; P = 0.03 and 98 +/- 39 vs. 124 +/- 54 mmHg; P = 0.04, respectively), reduced amplitude of slow waves (7.3 +/- 3 ts. 9.5 +/- 3.7 mmHg; P = 0.03), anal leak in smaller rectal volumes (P = 0.003), and reduced response of the anal sphincter at the anocutaneous reflexes (29 +/- 14 vs. 39 +/- 14 mmHg; P = 0.05) compared with Group A. The former group of patients exhibited a significantly higher incidence of fecal incontinence (P = 0.008).

CONCLUSION

Patients with long-standing diabetes mellitus have increased incidence of fecal incontinence and severely impaired function of both the anal sphincters and the rectum. These findings could be attributed to the increased incidence of microangiopathy and autonomic and peripheral neuropathy observed in this subset of diabetic patients.

AGA technical review on anorectal testing techniques

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Clinical Practice and Practice Economics Committee. Following external review, the paper was approved by the committee on May 17, 1998.

Anal sensitivity test: what does it measure and do we need it? Cause or derivative of anorectal complaints

PURPOSE

This study was undertaken to determine the anal sensitivity in controls and in different patient groups and to establish factors that determine anal sensitivity.

METHODS

Anorectal function tests were performed in 387 patients with different anorectal diseases. Anal sensitivity was measured in 36 controls. Anal sensitivity was measured by means of mucosal electrosensitivity (MES) using a catheter with two electrodes placed in the anal canal. A constant current (square wave stimuli 100 microsec, pulses per second) was increased stepwise from 1 to 20 mAmp until the threshold sensation was reached. Other tests used were anal manometry (maximum basal pressure, maximum squeeze pressure, rectal compliance (maximum rectal volume and pressure), endosonography (submucosal thickness), defects and thickness of internal and external sphincter), electromyography (maximum contraction pattern, Grade 1 (solitary contractions) to Grade 4 (interference pattern)), and pudendal nerve terminal motor latency. Multiple regression analysis was performed. It was postulated that age, local conditions (anal scars, anal fissures, hemorrhoids, mucosal prolapse, proctitis, sphincter thickness and defects, and submucosal thickness), and neurologic factors could influence anal sensitivity.

RESULTS

Controls had an MES of 3.4 +/- 1.7. MES was significantly increased compared with controls in patients with fecal incontinence, soiling, hemorrhoids, mucosal prolapse, constipation, anal scars, anal surgery, and sphincter defects; patients with fecal incontinence had the highest MES (6.7 +/- 4.3; P < 0.0001). Patients with anal fissures and proctitis showed no differences compared with controls. MES correlated significantly with age (R = 0.29), maximum basal pressure (R = -0.29), maximum squeeze pressure (R = -0.32), submucosal thickness (R = 0.19), maximum contraction pattern (R = -0.39), single-fiber electromyography (R = 0.39), and maximum rectal volume and pressure (0.14). Multiple regression analysis showed that age, internal sphincter defects, and submucosal thickness significantly influenced anal sensitivity, but explained only 10 percent of the variance.

CONCLUSION

Anal sensitivity is diminished in all patients with anorectal diseases except for anal fissures and proctitis. There are correlations with other anorectal function tests. Anal sensitivity is determined for 10 percent by age, internal sphincter defects, and thickness of the submucosa. Anal sensitivity measurement, therefore, has limited clinical value and should be used in conjunction with other tests in a research setting.

Pudendal neuropathy in diabetic patients with faecal incontinence

To investigate the pathophysiology of faecal incontinence in diabetes mellitus, two groups of diabetic patients were studied: 14 subjects (7 females and 7 males, mean age 57 +/- 9 years) with faecal incontinence (Group A) and 15 subjects (6 females and 9 males, mean age 54.7 +/- 8 years) without faecal incontinence but affected by somatic peripheral neuropathy. A third group (C) of 10 healthy volunteers was used as controls. All subjects underwent electroneurographic evaluation of peripheral neuropathy, pudendal nerve terminal motor latency, anorectal manometry and rectal sensitivity tests. All the patients of group A had somatic peripheral neuropathy. Maximum squeeze pressure was lower in A compared to C (P < 0.025) and sustained for a shorter period in A compared with B (P < 0.0005) and C (P < 0.0005). All rectal sensitivity thresholds were higher in A compared with B and C. Pudendal Nerve Terminal Motor Latency was prolonged in 93% of patients studied in group A and in 73% of patients in group B (A vs B P < 0.005), with a significant difference in comparison with C: A vs C P < 0.0005, B vs C P < 0.005. Our findings suggest that somatic neuropathy plays an important role in faecal incontinence in diabetic patients, combined with sensation threshold impairment as a feature of an autonomic involvement.

Anorectal function

A review in a historic perspective of the present knowledge of anorectal physiology is presented. The techniques used in the anorectal physiology laboratory are discussed. Application of new sophisticated techniques to anorectal physiology research in recent years continue to improve our knowledge of anorectal function. Anal continence and defecation depend on both the anal sphincter and the rectum. The assessment of patients with functional anorectal diseases should include a more complete physiologic evaluation of the anorectum than used previously.