Clinical trial NCT01300897: Investigation of Cortico-Rectal Pathways in Healthy Subjects and Constipated Patients
Official title: Investigation of Cortico-Rectal Pathways in Healthy Subjects and Constipated Patients
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Healthy Volunteers
Constipation
Keywords: cortical evoked potentials, motor evoked potential responses
Lead sponsor: Augusta University
Sponsor class: OTHER
First posted: 2011-02-23
Enrollment: 150
Sex: ALL
Minimum age (years): 18
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: 40 Healthy volunteers. 110 patients with chronic constipation and dyssynergic defecation and rectal hyposensitivity and rectal hypersensitivity

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.

Eligibility criteria: Inclusion criteria:

* Right-handed adults between ages 18 years and 99 years, who are free of bowel disorders or other medical illnesses.

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.

Primary outcomes:
measure: Describe latencies and amplitudes between the brain and gut in healthy volunteers
timeFrame: 1 visit of 3 hours
Secondary outcomes:
Other outcomes:
Locations:
city: Iowa City
country: United States
facility: University of Iowa Hospitals and Clinics
state: Iowa
Study officials:
affiliation: Augusta University
name: Satish SC Rao, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: