Electrical stimulation of the urethra evokes bladder contractions in a woman with spinal cord injury.
OBJECTIVE
Electrical stimulation of pudendal urethral afferents generates coordinated micturition in animals and bladder contractions in men after spinal cord injury (SCI), but there is no evidence of an analogous excitatory urethra-spinal-bladder reflex in women. The objective of this study was to determine whether electrical stimulation of the urethra could evoke bladder contractions in a woman with SCI.


METHODS
A 38-year-old woman with a C6 ASIA A SCI who managed her bladder with clean intermittent catheterization and oxybutynin demonstrated neurogenic detrusor overactivity on urodynamics. Oxybutynin was discontinued 2 days prior to urodynamic testing with a custom 12F balloon catheter mounted with ring-shaped electrodes located in the bladder neck, mid urethra, and distal urethra. The inflated balloon was placed against the bladder neck to stabilize the catheter electrodes in place along the urethra. However, the balloon limited emptying during contractions. Urodynamics were performed at a filling rate of 25 mL/minute until a distention-evoked bladder contraction was observed. The urethra was stimulated over a range of bladder volumes and stimulus parameters to determine whether electrical stimulation could evoke a bladder contraction.


RESULTS
Electrical stimulation via urethral electrodes evoked bladder contractions that were dependent on bladder volume (>70% capacity) and the intensity of stimulation.


CONCLUSIONS
This is the first report of an excitatory urethra-spinal-bladder reflex in a woman with SCI. Future studies will determine whether this reflex can produce bladder emptying.
Kennelly
Michael J
MJ
Urology Department, Charlotte Institute of Rehabilitation, Charlotte, North Carolina 28203, USA. mkennelly@carolinas.org
Arena
Kimberly C
KC
Shaffer
Nell
N
Bennett
Maria E
ME
Grill
Warren M
WM
Grill
Julie H
JH
Boggs
Joseph W
JW
D000328:Adult; D001703:Biophysics / Q000379:methods; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D013119:Spinal Cord Injuries / Q000628:therapy*; D014521:Urethra / Q000502:physiology*; D001743:Urinary Bladder / Q000502:physiology*; D014554:Urination / Q000502:physiology