Pudendal neuromodulation for incontinence and sphincter dyssynergia after spinal injury

Spinal cord injurySCIfrequently produces severelife long bladder and bowel dysfunction that result in urinary and fecal incontinenceas well as sphincter dyssynergia that causes urinary retention and fecal impactionCurrent standard of care for incontinence consists of adult diaperswhile bladder and bowel voiding require multiple times daily catheterization of the bladder and regular digital extraction of fecesDiapers are odiferouscatheters induce frequent urinary tract infectionsand digital bowel programs are time consuming and stigmatizing for the individual and or their caregiverFor most people with SCIbladder and bowel dysfunction impacts their professional and social lives more than their inability to walkIn this applicationwe propose that currently availableprogrammableimplantable pulse generatorsIPGsinterfaced with electrodes placed bilaterally on the pudendal nervescan offer people with SCI a remedy for both incontinence and sphincter dyssynergiaThe pudendal nerve provides efferent innervation to the urethral and anal rhabdosphincters that produces contractions and prevents the leakage of urine and feces through the urethra and anal canalrespectivelyIn this applicationwe focus on improving urinary function and propose that stimulation of the pudendal nerve at low frequenciesLFSwill produce urethral sphincter contractions that resist flow of urine and prevent urinary incontinenceWe further propose that LFS will also activate pudendal afferent fibers to suppress bladder overactivity through spinal mechanismsWhen voiding is desiredwe propose that briefminintermittentdaypudendal nerve stimulation at highkHzfrequenciesKHFSwill occlude pudendal nerve action potentials and prevent sphincter dyssynergia to allow voidingUnilateral stimulation of the pudendal nerve was found clinically safe and efficacious for treating various urogenital dysfunctionsbut bilateral stimulationwhich is necessary to fully contract the sphincterhas not been attemptedSpecific Aimwill establish the most efficient LFS pulse characteristics needed to provide maintained urethral sphincter contractions to prevent leakage of urine during periods of elevated bladder pressureStorage ModeSpecific Aimwill explore whether the LFS pulse characteristics that activate efferent fibersto contract the sphinctercan also provide effective stimulation of the afferent fibersto inhibit bladder overactivitySpecific Aimwill establish if the same electrodes used for LFS can also deliver KHFS to block pudendal nerve activityrelax the sphincterand facilitate voidingVoiding ModePhasestudies using implanted IPGs for long term behavioral studies of urinary function in a preclinicaltranslational model of chronic SCI will also establish if the device simultaneously improves bowel function Individuals with spinal cord injury suffer from bladder and bowel dysfunction that result in life long urinary and fecal incontinenceas well as urinary retention and fecal impactionTheir inability to control bladder and bowel function often restricts their professional and social lives more than the inability to walkThese studies are the first step to creating a device that can prevent incontinence and improve voidingThis Phaseapplication focuses on improving urinary functionbut Phasestudies will include assessment of the deviceandapos s ability to also improve bowel function in a preclinicaltranslational model of chronic spinal cord injury