Intermittent Versus Continuous Stimulation in Bilateral Sacral Neuromodulation for Overactive Bladder

The objective of this project is to investigate the outcomes of intermittent versus continuous stimulation in patients treated with sacral neuromodulation (SNM) for refractory overactive bladder (OAB) syndrome. In addition, the potential for an improved battery life with intermittent stimulation will be quantified. Manufacturers recommended settings for newly implanted impulse generators (IPG); however, no standardized recommendations exist for further adjustments. Quality studies examining IPG parameters are lacking, partly due to the numerous setting variables, which can result in a multitude of permutations. When programming an IPG, an option for cycling simulation (16 seconds on, 8 seconds off) is available. It is theorized that because of a "carryover" effect, symptom relief will continue despite the stimulator being off. The potential benefit of the intermittent stimulation is an improved battery life, which may translate into a less frequent need for reimplantation with less morbidity. Participants receiving neuromodulation treatment for overactive bladder symptoms will be routinely fitted with an impulse generator in a pre-study phase. Patients who experience significant symptomatic improvement will receive a full bilateral sacral neuromodulator implantation and will be randomized to either intermittent or continuous stimulation. Participants will fill out voiding logs and surveys over a 12 week period. At that point, a one-week washout period during which the neuromodulator will be turned off. The impulse generator will then be turned to the alternate setting (intermittent or continuous) and the 12 week period will be repeated. Questionnaires and voiding diaries will be collected at each clinic visit. In total, subject participation will last approximately 25 weeks after full implantation of the bilateral leads and pulse generator.