Electrical stimulation of somatic afferent nerves in the foot increases bladder capacity in neurogenic bladder patients after sigmoid cystoplasty

Background: A previous study showed that foot stimulation can delay the bladder filling sensation and increase bladder volume in healthy humans without OAB. The aim of this study was to determine whether or not electrical stimulation of somatic afferent nerves in the foot can increase bladder capacity in neurogenic bladder patients after sigmoid cystoplasty. Methods: Eleven subjects underwent 30-min foot stimulation using skin surface electrodes connected to a bladder-pelvic stimulator. The electrodes were attached to the bottom of the foot. The subjects completed a 5-day voiding diary, during which time foot stimulation was applied on day 3. The stimulation parameter was a continuous, bi-polar square wave form with a pulse duration of 200 mu s and a stimulation frequency of 5 Hz. The stimulation intensity was set by each subject at a maximal level without causing discomfort. Results: The volume per clean intermittent catheterization (CIC) was 279.4 +/- 11.7 ml and 285.4 +/- 11.8 ml on the 1st and 2nd days, respectively. On the 3rd day, the average volume per CIC increased to 361.1 +/- 18.1 ml after stimulation (p < 0.05). The average volume per CIC returned to 295.4 +/- 13.4 ml and 275.1 +/- 11.5 ml on the 4th and 5th days, respectively. Conclusions: Foot stimulation can delay the bladder filling sensation and significantly increase bladder capacity in neurogenic bladder patients after sigmoid cystoplasty.