Selective co-stimulation of pudendal afferents enhances bladder activation and improves voiding efficiency.
OBJECTIVE
Clinical application of pudendal nerve (PN) afferent stimulation to restore bladder emptying in persons with neurological disorders requires increased stimulation-evoked voiding efficiencies (VEs). We tested the hypothesis that selective co-stimulation of multiple PN branches, either bilateral dorsal nerve of the penis (DNP) stimulation or selective stimulation of both the cranial sensory nerve (CSN) and DNP, will evoke larger reflex bladder contractions and result in higher VEs than stimulation of any single afferent pathway alone.


METHODS
We measured the strength of bladder contractions, threshold volumes, and VEs produced by unilateral and bilateral stimulation of the DNP as well as singular and selective unilateral co-stimulation of the DNP and CSN in cats anesthetized with α-chloralose.


RESULTS
Co-stimulation of afferent pathways generated significantly larger isovolumetric bladder contractions and evoked contractions at lower threshold volumes than individual stimulation. Co-stimulation of pudendal afferents also suppressed dyssynergic activity in the external anal sphincter produced by low frequency individual stimulation. VE was significantly improved with co-stimulation (172 ± 6% of distention evoked volumes) over individual stimulation (141 ± 6%).


CONCLUSIONS
Both types of co-stimulation evoked larger bladder contractions and increased VE over individual branch PN afferent stimulation and distention-evoked voiding. The decreased threshold volumes required for reflex bladder activation and increased VEs with co-stimulation support the use of stimulation of multiple individual stimulation-evoked reflexes to improve voiding efficiency.
Department of Biomedical Engineering, Duke University, Durham, North Carolina.
Meredith J
MJ
McGee
Warren M
WM
Grill
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D002415:Cats; D004558:Electric Stimulation / Q000379:methods*; D008297:Male; D060525:Pudendal Nerve; D012018:Reflex; D001743:Urinary Bladder / Q000502:physiology*; D014554:Urination / Q000502:physiology*
electrical stimulation; reflex; spinal cord injuries; urinary retention; urination