Neurogenic bowel as a sequela of spinal cord injury (SCI) is characterized by difficulty with evacuation, chronic abdominal pain, and fecal incontinence. Gastrointestinal (GI) dysfunction and related symptoms can have significant adverse repercussions on emotional, occupational, community, and social functioning. There have been few advances in bowel care technology in the past decade, and dissatisfaction with bowel care management is prevalent amongst individuals with SCI. Bowel biofeedback is a novel and promising therapeutic approach which has been shown to improve constipation, fecal incontinence, and dyssynergic defecation in the general population. The concept of biofeedback is based on principles of operant conditioning, in which information concerning a normally subconscious physiological function is consciously relayed to patients, allowing them to become actively engaged in learning to consciously control this function. While the symptoms of bowel dysfunction in persons with SCI are well known, there are limited studies to date looking at anorectal (AR) function and motility. Various techniques, such as the measurement of pressure profiles during volitional activity, can facilitate assessment of GI fine motor function. These pressure assessments are known as manometric studies, and they can provide valuable information about AR physiology. In the past, water-perfused manometric systems were limited by widely spaced, unidirectional sensors, which were incapable of capturing detailed events in small, activity laden areas, such as the AR. High resolution manometry (HRM) uses tight sensor spacing and 3-D topographical representation to provide detailed information concerning sphincter strength, defecation dynamics and reflex mechanisms in the AR. To date, AR-HRM studies have not been conducted in a SCI population. In this pilot proposal, HRM will be initially employed (Part 1) to identify manometric profiles of persons with SCI, and to identify bowel phenotypes--that is, clusters of physiologic characteristics that are present in each individual which are based on HRM findings. Secondarily (Part 2), 6 weeks of biofeedback training will be performed in a subset of individuals who participated in Part 1 of the study, and to compare manometric profiles pre-post training. Finally, we will assess the effects of 6 weeks of home biofeedback exercises on bowel function by manometric evaluation to determine if the gains from this home bowel training can be sustained.
The Specific Aims for Part 1 of this study are (1) to identify each subject?s functional bowel phenotype based on AR-HRM findings (baseline sphincter tone, response to balloon distension test, strength of defecation and retention maneuvers) and compare to able-bodied bowel phenotypes, (2) to determine the correlation of baseline AR-HRM characteristics with SCI completeness and lesion level, (3) and to determine the correlation of baseline AR-HRM characteristics with the 10 Question Bowel Survey (10Q-BS) score and Wexner?s Incontinence Score (WIS).
The Specific Aims for Part 2 of this study are (1) to perform 6 weeks of supervised bowel biofeedback training in a subset of SCI subjects with incomplete levels of injury who participated in Part 1, (2) to assess the efficacy of bowel biofeedback after 6 weeks of home exercise, (3) to assess changes in AR-HRM characteristics pre and post each treatment period, and (4) to correlate baseline neurological and AR-HRM characteristics with post-treatment outcomes to determine factors that best predict treatment outcome. If bowel biofeedback is found to be an effective means for the reduction/prevention of incontinency or the reduction in DWE during bowel care, this novel method could be clinically offered as therapy, which would reduce reliance on purgatives and curtail maladaptive social avoidance. Additionally, if such benefits can be maintained through simple home bowel biofeedback exercises, this approach to bowel care would represent a novel, efficacious, and accessible form of therapy that many individuals suffering from neurogenic bowel could benefit from, without the burden of continuously attending clinical training sessions.
Spinal cord injury (SCI) is characterized by a number of secondary medical conditions, including the loss of bowel control. For most individuals with SCI, bowel management is time consuming and cumbersome. Despite their efforts, these routines are only partially successful, and many individuals with SCI remain chronically constipated, and some experience fecal incontinence. The pathophysiology of bowel dysfunction in SCI has not been clearly defined due, in large part, to technological hurdles. Recently, the development of high resolution manometry (HRM) will allow us to document in greater detail, anorectal pathophysiology, and to assess treatment outcomes based on precise manometric findings. We propose to categorize anorectal function in persons with SCI using HRM and to test the efficacy of biofeedback treatment and home therapy in improving objective (HRM parameters) and subjective (self-reported symptoms) endpoints. If successful, this approach would represent a therapeutic alternative approach to bowel care in the SCI population.
