Superficial Peroneal Nerve Neuromodulation for Non-Obstructive Urinary Retention
Superficial Peroneal Nerve Neuromodulation for Non-Obstructive Urinary Retention
Millions of Americans are suffering from underactive bladder (UAB). The impact of severe UAB,
 i.e. non-obstructive urinary retention (NOUR) on quality of life is significant because
 current treatment for non-obstructive urinary retention requires intermittent
 self-catheterization or an indwelling suprapubic catheter. Currently an effective drug for
 non-obstructive urinary retention does not exist. It is a therapeutic challenge for
 clinicians to successfully treat non-obstructive urinary retention. Sacral neuromodulation
 has been approved by the FDA since 1999 to treat non-obstructive urinary retention. It
 achieves >50% improvement in bladder emptying (reducing the frequency of self-catheterization
 or increasing voided volume) in just over half of the patients. Sacral neuromodulation
 requires surgical implantation of a stimulator and a lead with 4 electrodes. The surgery and
 implant are invasive and expensive, preventing a broad application of this effective therapy
 to many non-obstructive urinary retention patients. The goal of this study is to develop a
 novel non-invasive neuromodulation therapy for non-obstructive urinary retention as an
 alternative. Specifically, the investigators will explore the possibility to translate into
 humans a recent discovery in cats of an excitatory reflex from the superficial peroneal nerve
 to the bladder to treat non-obstructive urinary retention. Therefore, in this study the
 investigators propose to develop a non-invasive, transcutaneous neuromodulation therapy for
 non-obstructive urinary retention that can be administered at home.
Hypothesis: Electrical stimulation of the superficial peroneal nerve using transcutaneous
 skin electrodes attached on the dorsal foot can treat non-obstructive urinary retention
 either by enhancing bladder sensation thereby reducing bladder volume needed for initiating
 voiding and/or by enhancing bladder contraction, thereby increasing voiding efficiency and
 reducing post-void residual (PVR) volume.

 Rationale: The investigators conducted preliminary studies in cats that have demonstrated an
 excitatory reflex to the bladder elicited by stimulation of afferent axons in the superficial
 peroneal nerve. Activating this excitatory reflex in cats reduced bladder capacity (the
 minimal volume for initiating a micturition reflex), enhanced bladder contractions and
 overcame bladder inhibition emanating from somatic (tibial) afferent activation. Since the
 superficial peroneal nerve innervates the dorsal skin of the foot in humans, it can be
 stimulated non-invasively by skin surface electrodes. Transcutaneous stimulation of this
 nerve, should it prove efficacious, would likely be more acceptable to patients with
 non-obstructive urinary retention (NOUR) than invasive sacral neuromodulation therapy.
 Therefore, in this study, the investigators propose to test the superficial peroneal nerve
 neuromodulation in non-obstructive urinary retention patients.

 Specific Aim: Determine the efficacy of superficial peroneal nerve stimulation (SPNS) in the
 treatment of patients with non-obstructive urinary retention using skin electrodes attached
 to the dorsal surface of the foot.

 Rationale: Based on a preliminary discovery in cats, the investigators propose to further
 investigate the effect of superficial peroneal nerve stimulation (SPNS) on voiding
 efficiency, post-void residual (PVR) volume, and bladder capacity (voided volume + post-void
 residual) in patients with non-obstructive urinary retention. A reduced bladder capacity
 indicates more normal bladder filling sensations, thereby allowing voiding at more normal
 volumes. The investigators plan to test superficial peroneal nerve stimulation in 20
 non-obstructive urinary retention patients by collecting voiding diary during a 3-week
 period. Baseline voiding diary will be collected during the first week before superficial
 peroneal nerve stimulation initiation. During the second week, superficial peroneal nerve
 stimulation will be administered to each patient for 3 hours/day before sleep and it will
 also be administered immediately prior and throughout each void. The 3-hour stimulation is
 designed to modulate bladder sensory pathways to enhance bladder sensation, thereby reducing
 the bladder volume required to initiate voiding. The acute stimulation during each void is
 designed to enhance bladder contraction, thereby increasing voiding efficiency and reducing
 post-void residual. During the third week, superficial peroneal nerve stimulation will not be
 applied, and a voiding diary will be collected to determine any post-stimulation effect.
 Since the superficial peroneal nerve is a cutaneous nerve innervating the skin of the dorsal
 foot, superficial peroneal nerve stimulation will be applied non-invasively by attaching skin
 surface electrodes to the dorsal side of the foot.
Inclusion Criteria:

 Able to provide informed consent

 1. 18 years of age and older

 2. Clinically diagnoses as non-obstructive urinary retention

 3. Post Void Residual of 300 mL or greater

 4. Currently using daily self-catheterization to empty the bladder

 5. Capable of using the toilet independently without difficulty

 6. Capable and willing to follow all study-related procedures

 Exclusion Criteria:

 1. Neurologic diagnosis (including diabetes mellitus)

 2. Surgery within one year of screening for urinary outlet obstruction

 3. Pregnant or planning to become pregnant during study duration

 4. OnabotulinumtoxiA use in bladder or pelvic floor muscles with the past year

 5. Pacemaker or implantable defibrillator

 6. Current Urinary tract or vaginal infections

 7. Current Interstim use

 8. Current Percutaneous tibial nerve stimulation (PTNS) or transcutaneous electrical
 nerve stimulation (TENS) use in pelvis or back or legs

 9. Investigational drug/ device therapy with the past 4 weeks,

 10. Participation in any clinical investigation involving or impacting gynecologic or
 urinary function with the past 4 weeks,

 11. Previous surgery of or damage to the foot or nerves in the foot and leg.