The sight or sound of running water can trigger urinary urgency in some individuals with overactive bladder (OAB) [1]. There are limited studies investigating the effects of audio-visual stimuli on the sensation of bladder fullness. The purpose of this study was to test the hypothesis that individuals with OAB experience greater increases in bladder sensation in response to the sight and sound of running water compared to individuals without OAB.

Participants were recruited into a prospective oral hydration study. Participants completed the International Consultation on Incontinence Questionnaire on OAB (ICIq-OAB), and their responses to question 5a about how often they rush to the toilet were used to divide them into groups with OAB (5a≥2) and without OAB (5a=0). Participants also completed a standardized trigger survey asking how often the sight or sound of running water makes them rush to the toilet using the same 0-4 scale as the ICIq-OAB (0=never, 1=occasionally, 2=sometimes, 3=most of the time, and 4=always). After filling out both the ICIq-OAB and trigger surveys, participants completed an oral hydration protocol with three complete bladder fill and void cycles (Fill1-Fill3). They drank 2L Gatorade G2 as quickly as possible during Fill1 and replaced the volume voided by drinking an equivalent volume of water during the beginning of Fill2 and Fill3 in order to maintain maximum diuresis. Throughout filling, participants recorded their sensation of bladder fullness on a 0%-100% scale using a previously-developed tablet-based sensation meter [2, 3]. After reaching 50% sensation during Fill1 and Fill3, participants watched a 3-minute trigger video showing sights and sounds of flushing toilets, running water, fountains, rain, waterfalls and swimming. (Fig. 1). The change in percent sensation from the beginning to the end of the trigger video was calculated for each group. Fisher’s exact test was used to identify statistical associations between participant groups.

Trigger Survey Results: Twelve individuals without OAB and eleven individuals with OAB completed the trigger survey. All twelve individuals without OAB reported minimal responses to the sight or sound of running water (score of 0 or 1), while 10 of 11 individuals with OAB reported heightened responses (score of ≥2). A response of ≥2 was significantly associated with OAB (Fisher’s exact test, p<0.05). 

Trigger Video Results: Fourteen individuals without OAB and eleven with OAB completed the hydration study and were exposed to the trigger. Fill1 was slower than Fill3 for each group (10 vs. 17 ml/min for those without OAB, and 6 vs 14 ml/min for those with OAB, p<0.05).  During both Fill1 and Fill3, none of the individuals without OAB exhibited an increase in sensation of ≥30% during the trigger video. In contrast, two of the eleven (18%) individuals with OAB reported a sensation increase of ≥30% during the trigger video in the slower Fill1, and four of eleven (36%) reported an increase of ≥30% during the trigger video in the faster Fill3.  This increase of ≥30% in bladder sensation during the trigger video in Fill3 was significantly associated with OAB (p<0.05)
  
Correlation Between Trigger Survey and Trigger Video Results: Changes in sensation during the trigger video were also compared to trigger survey responses. All four individuals (100%) that exhibited an increase of ≥30% sensation during the trigger video in Fill3 responded with a survey score of ≥2 for the sight or sound of running water. In contrast, six of nineteen individuals (32%) that exhibited a <30% change in sensation during the trigger video in Fill3 responded with a survey score of ≥2 for the sight or sound of running water. A sensation increase of ≥30% during the trigger video was significantly associated with greater survey responses for the sight or sound running water during Fill3 (p<0.05).

The results of this study suggest that some participants with OAB may have heightened sensation due to audio-visual stimuli of running water compared to individuals without OAB. Heightened responses to the trigger video of running water correlated with the trigger survey question results, indicating that individuals are aware of their sensitivity to this environmental trigger of urgency.

The results of this study indicate that the incorporation of environmental triggers into a non-invasive hydration protocol may help identify an OAB subgroup affected by triggers of urgency such as the sight or sound of running water. Further research is needed to understand the effects of environmental triggers on bladder sensation in individuals with OAB.

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Nagle, A.S., et al., Non-invasive characterization of real-time bladder sensation using accelerated hydration and a novel sensation meter: An initial experience. Neurourology and Urodynamics, 2017. 36(5): p. 1417-1426.
Sheen, D., et al., Validation of a real-time bladder sensation meter during oral hydration in healthy adults: Repeatability and effects of fill rate and ultrasound probe pressure. LUTS: Low Urinary Tract Symptoms, 2019. 11(4): p. 224-231.