# Pudendal neuromodulation for urinary and fecal incontinence and sphincter dyssynergia

> **NIH NIH R44** · DIGNIFY THERAPEUTICS, LLC · 2020 · $941,206

## Abstract

SUMMARY / ABSTRACT
 Spinal cord injury (SCI) frequently produces severe, life-long bladder and bowel dysfunction that results in
urinary (UI) and fecal incontinence (FI), as well as sphincter dyssynergia that results in urinary retention and
fecal impaction. Current standard of care for incontinence consists of modestly effective drugs, complicated
surgery, or adult diapers. Bladder and bowel voiding require multiple-times-daily catheterization of the bladder
and regular digital extraction of feces for most SCI individuals. Diapers are odiferous, catheters induce
frequent urinary tract infections, and digital bowel programs are time-consuming and stigmatizing for the
individual and/or their caregiver. For most people with SCI, bladder and bowel dysfunction impacts their
professional and social lives more than their inability to walk.
 Our Phase 1 STTR application, in anesthetized preparations, determined electrical pulse characteristics
(e.g. 3T, 100 usec, 10-30 Hz), which when applied to the pudendal (PUD) nerve, stimulated efferent and
afferent fibers to produce, respectively, sustained contractions (>1 hour) of the urethral and anal sphincters
and inhibition of bladder activity with increased bladder capacity. Bladder leak point pressures were also
markedly increased. These physiological effects should significantly reduce UI and FI when replicated in
patients. In addition, the same electrodes and stimulator that were used to stimulate the PUD nerve were also
able to block the PUD nerve by switching from low frequency to kHz high frequency (constant duty cycle)
pulses that prevented sphincter contractions.
 In Aim 1 of this Phase 2 SBIR application, chronic SCI preparations are first tested to confirm that they
respond to the above pulse characteristics similarly to our Phase 1 study in spinal intact studies. For Aim 2, a
translational study is performed in which an implantable pulse generator (IPG), is interfaced with electrodes
placed bilaterally on the pudendal nerves of chronic SCI preparations for 2 months. During this time, the IPG
is used to stimulate the PUD nerve when “Storage” of urine and feces is desired and then switched to block the
PUD nerve when “Voiding” of urine and feces is desired. The IPG uses a remote control to switch between
Storage Mode and Voiding Mode. Effectiveness in controlling UI and FI episodes is assessed by comparing
the number and volume/weight of episodes on test days, with versus without, activation of Storage Mode.
Effectiveness for controlling sphincter dyssynergia is assessed by measuring drug-induced voiding efficiency
and subjective ratings of Credé difficulty on test days, with versus without, activation of Voiding Mode. At the
end of the study sphincters are evaluated for signs of sphincter muscle hypertrophy and increases in fatigue-
resistant muscle fibers. Finally, in preparation for FDA discussions, we will assess different preparations in
consideration of GLP safety studies.

## Key facts

- **NIH application ID:** 10154256
- **Project number:** 2R44NS115169-02
- **Recipient organization:** DIGNIFY THERAPEUTICS, LLC
- **Principal Investigator:** KARL B THOR
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $941,206
- **Award type:** 2
- **Project period:** 2019-09-30 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10154256

## Citation

> US National Institutes of Health, RePORTER application 10154256, Pudendal neuromodulation for urinary and fecal incontinence and sphincter dyssynergia (2R44NS115169-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10154256. Licensed CC0.

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