Sacral Neuromodulation in Dual Incontinence: Ultrasound and Afferent Nerve Sensation Assessment

One in four women reports bothersome symptoms of a pelvic floor disorder with 16% reporting
urinary incontinence (UI), otherwise known as leakage. Likewise, 1 in 5 women with UI reports
fecal incontinence (FI). Women with dual incontinence (UI/FI) often have more bothersome
symptoms, quality of life impact, and sexual dysfunction than those with just UI or FI. In
many situations, bladder and/or bowel control problems are the result of a failure of
communication between the brain and the sacral nerve. The sacral nerve controls the bladder,
bowel, and pelvic floor and the muscles related to their function. If the brain and sacral
nerve do not communicate correctly, the bladder and/or bowel cannot function properly, which
often leads to incontinence, or leakage. The only currently available treatment with level 1
effectiveness data for the treatment of BOTH UI and FI is called Sacral Neuromodulation.
Sacral Neuromodulation (SNM) is a standard of care procedure used to treat men and women that
have symptoms of Urinary and Fecal Incontinence and involves surgically implanting a device
in to the patient's body to target this communication problem by stimulating the nerves that
control bladder and bowel function with mild electrical pulses. This helps the brain and
nerves to communicate so the bladder and bowel can function properly. It is known that
changes in nerve stimulation and muscular function are important factors in the cause and
onset of UI and FI and in how a patient will respond to various treatments, however, the
precise mechanism of action of SNM on UI and FI remains unclear.

This study therefore aims to obtain a better understanding of nerve and muscle function in
patients with dual incontinence and to quantify how SNM affects the nerves of patients with
dual incontinence. We hope to do so by using Current Perception Threshold (CPT) Testing,
which is a way to quantify the function of different populations of afferent nerves. We will
recruit patients who already plan on undergoing Sacral Neuromodulation implantation for the
treatment of their dual incontinence, and as part of the research study we will use CPT
testing to measure the amount of stimulation required to activate the participant's sacral
nerve before SNM and will also measure the current perception threshold of the participant's
sacral nerve after SNM treatment. We expect to see a difference in the amount of stimulation
required to activate different pelvic floor nerves before and after the device implantation.
By learning more about nerve function in patients with DI, we hope to find a way to screen
patients before treatment with SNM to make sure the treatment will work for them. We also
hope to learn how urethral and anal sphincter anatomy in patients with dual incontinence
changes after treatment with SNM. Lastly, we will study the quality of sexual relationships
in women with dual incontinence and their male partners and attempt to identify specific
areas of dysfunction that are common in patients with DI.

Inclusion Criteria:

- Subject is a female over the age of 18 years old

- Subject is diagnosed with idiopathic dual incontinence

- Subject is planning to undergo placement of a sacral nerve modulator

- Subject has at least 5 UUI episodes on a 3-day diary

- Subject has 2 FI episodes on a 7-day diary

- Subject has given signed, informed consent prior to registration on study

Exclusion Criteria:

- Subject has a neurologic disease

- Subject has a disease that may impair sphincter tone or sensation

- Subject is pregnant

- Subject has > Stage II pelvic organ prolapse

- Subject underwent rectal surgery in the past year

- Subject has chronic inflammatory bowel disease

- Subject has diathermy

- Subject has QTc prolongation

- Subject has cardiac arrhythmia