Hypothesis / aims of study
Urgency Urinary Incontinence (UUI) and overactive bladder (OAB) can seriously impact quality of life, and health in older adults While many UUI episodes are unpredictable, reports of regular scenarios that trigger urgency and leakage are common. These scenarios are familiar to clinicians, most commonly reported as urgency or ‘situational’ incontinence experienced upon arriving at one’s front door (e.g., 'latch-key incontinence’) or hearing running water. It has been reported that up to 52% of participants in a study of women with UUI experienced urgency from situational cues with 26% of those also experiencing leakage[1]. We have proposed that OAB in response to environmental cues is a conditioned response which often starts younger and worsens with age. For example, a lifetime routine of waiting to use one’s own bathroom upon arriving home (unconditioned stimulus) can result in the arrival point (front/garage door) becoming a conditioned stimulus, eliciting the conditioned response of DO, urgency, or leakage. This effect is compounded by age; increased duration of conditioning coupled with reduced pelvic floor tone and cognitive focus. Bladder-centric treatments do not consider conditioned cues and may be less effective on triggered urgency and leakage episodes. Given that UUI sufferers often experience both physiologically driven and conditioned reactivity, adjunct treatment methods targeting conditioned responses will likely augment UUI treatment efficacy could significantly reduce UUI burden.
Studies of the brain-bladder connection have revealed that the brain has an important role in the continence mechanism, both at a basic lower urinary tract control level, and at a psychological level. Using our current understanding of the brain’s role in continence and conditioning processes, we developed a behavioral therapy that used a specially developed mindfulness technique, brain stimulation of the prefrontal cortex—the center of executive control of the bladder—and exposure to participant-generated personalized images of trigger situations to attenuate bladder-related responses to these urgency-provoking situations.
Here we report the results of that randomized study on the effect of mindfulness (MI), transcranial direct current stimulation (tDCS) of the dorsolateral pre-frontal cortex and a combination of both to reduce reactivity to urgency and incontinence triggering situations.
Study design, materials and methods
Women aged 40 years and older who reported situational incontinence in at least 4 places were randomized to one of three groups: MI, tDCS or MI+tDCS.
Participants identified urgency-cue scenarios (e.g. key in front door, running tap) and safe scenarios (e.g. sofa, TV room) and took 4 high resolution photographs of each scenario from different angles (2 approaching and 2 from within the environment). Baseline assessment included a 3-day bladder diary and post-treatment assessment included a 7-day bladder diary, which recorded number of triggers, leaks, urgency episodes and voids. The intervention consisted of four in-office visits over 5-6 days during which the participants were exposed to their personalized urgency-cue images projected onto a wall. Each of the 4 cue images in a set was projected for 8 seconds and displayed in a fixed order to simulate the approach to the scenario; separate cue image sets were displayed in a randomized order and repeated for 20 minutes while participating in one of the following interventions:
1) MI – ‘bodyscan’ audio – active mindfulness practice using a bodyscan exercise which included but did not focus on the bladder
2) tDCS – 20 minutes of 2.0 mA anodal stimulation of the dorsolateral pre-frontal cortex using 25cm2 electrodes placed on the right temple and left bicep.
3) MI+tDCS – both interventions simultaneously.
Participants undergoing mindfulness (Group 1 & 3) were given the audio file on a small MP3 player with headphones to practice at home for three days before, and throughout, the intervention.
The mean number of leaks, urgency episodes, voids and triggers per day were calculated at baseline and post intervention. ‘Triggers’ were any episode that were deemed triggered by a situational cue on bladder diary. Analysis of variance was performed to identify group by time interactions, and post-hoc Tukey test was used to examine the effect of individual interventions.
Interpretation of results
Both mindfulness and tDCS were effective in reducing leakage episodes and the number of triggered episodes. The combination of the two interventions also significantly reduced urgency episodes. Of note, this study was the first trial of these novel interventions and was designed to assess acceptability and overall effectiveness of these behavioral interventions, and was not powered to assess differences in the effectiveness of the individual interventions. However, these results show that behavioral interventions to attenuate situational urgency and incontinence are effective and show promise. With the advent of smartphones and at home tDCS devices, these interventions can be tailored and disseminated widely.