Investigation of Cortico-Rectal Pathways in Healthy Subjects and Constipated Patients

• Conditions: Constipation; Healthy Volunteers
• Interventions: Procedure: Cortical Evoked Potentials; Procedure: Transcranial motor evoked potentials; Procedure: Translumbosacral motor evoked potentials

• Registration Number: NCT01300897
• Lead Sponsor: Augusta University

Brief Summary

Biofeedback therapy improves bowel symptoms and anorectal function in patients with dyssynergic defecation, however its mechanism of action is not known. The investigators hypothesize that biofeedback therapy enhances gut-brain-gut communication by altering cortical processing of information and improving cortically mediated neuromuscular function of the gut. However, in order to better understand these mechanisms in patients, the investigators need to examine and establish normative data and compare findings with healthy subjects. The investigators specific aims are to examine and evaluate the following 40 normal subjects; (1) To evaluate the afferent cortical evoked potentials in response to the electrical stimulation of the anorectum and (2) To evaluate the corticofugal tracts (efferent) by recording the anal and rectal electromyographic responses following noninvasive lumbosacral and transcranial magnetic stimulation.

Detailed Description

1. Cortical evoked potentials:A probe with 2 ring electrodes is placed in anus and rectum. A small amount of electrical current is passed. The cortical evoked responses to the anal and rectal electrical stimulation is measured from the scalp using a neurophysiology recorder.

2. Motor evoked potentials: A magnetic coil is placed on the scalp at the anorectal cortical site and discharged using magnetic energy. The anal and rectal motor evoked potentials are then measured using a probe with 2 ring electrodes.

Study Timeline

• Study Start: 2005-08
• Study First Submitted: 2010-08-18
• Study First Submitted QC: 2011-02-22
• Study First Posted: 2011-02-23
• Primary Completion: 2015-12
• Status Verified: 2018-07
• Last Update Submitted: 2018-07-20
• Last Update Posted: 2018-07-23
• Study Completion: 2018-12

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 150

Inclusion Criteria

Not provided

Exclusion Criteria

• Potential subjects with comorbid illnesses; severe cardiac disease, chronic renal failure or previous gastrointestinal surgery except cholecystectomy and appendectomy.
• Neurologic diseases e.g.; head injury, epilepsy, multiple sclerosis, strokes, spinal cord injuries.
• People who have metal in their skull or under the skull, or have metal in the back or hips.
• People who have a cardiac pacemaker, implanted defibrillator or medication pump.
• Impaired cognizance (mini mental score of < 15) and/or legally blind.
• Pregnant or likely to conceive during the course of the study. Women with potential for pregnancy must be willing to use contraceptive measures during the study.
• Previous pelvic surgery, rectocele repair, bladder repair, radical hysterectomy.
• Rectal prolapse or anal fissure or anal surgery.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Healthy Volunteer	Cortical Evoked Potentials	healthy volunteers will serve as controls. In each subject the cortical evoked potentials, transcranial motor evoked potentials and translumbosacral motor evoked potentials will be measured.
Healthy Volunteer	Transcranial motor evoked potentials	healthy volunteers will serve as controls. In each subject the cortical evoked potentials, transcranial motor evoked potentials and translumbosacral motor evoked potentials will be measured.
Healthy Volunteer	Translumbosacral motor evoked potentials	healthy volunteers will serve as controls. In each subject the cortical evoked potentials, transcranial motor evoked potentials and translumbosacral motor evoked potentials will be measured.
Constipated patients	Cortical Evoked Potentials	Patients with chronic constipation and rectal hypersensitivity or hyposensitivity and/or dyssynergic defecation.In each subject the cortical evoked potentials, transcranial motor evoked potentials and translumbosacral motor evoked potential will be measured
Constipated patients	Transcranial motor evoked potentials	Patients with chronic constipation and rectal hypersensitivity or hyposensitivity and/or dyssynergic defecation.In each subject the cortical evoked potentials, transcranial motor evoked potentials and translumbosacral motor evoked potential will be measured
Constipated patients	Translumbosacral motor evoked potentials	Patients with chronic constipation and rectal hypersensitivity or hyposensitivity and/or dyssynergic defecation.In each subject the cortical evoked potentials, transcranial motor evoked potentials and translumbosacral motor evoked potential will be measured

Primary Outcome Measures

Name	Time	Method
Describe latencies and amplitudes between the brain and gut in healthy volunteers	1 visit of 3 hours	Measurements \& Analysis: The latency, inter-peak latency and amplitude of each component of the cortical evoked potentials will be averaged to obtain group mean data.; Statistical Analysis: The paired t-test or Wilcoxon signed-rank test will be used to compare the latencies.; Lumbosacral and Transcranial Magnetic Stimulation (TMS) Data and Statistical Analysis: Mean latency and mean amplitude for each individual will be calculated.

Trial Locations

Locations (1)

University of Iowa Hospitals and Clinics; 🇺🇸 Iowa City, Iowa, United States