Strong Desire to Void and Balance in Older Women With Overactive Bladder

Falls have multifactorial etiologies in older people. Lower urinary tract symptoms (LUTS) are one of those, with an increase prevalence over years (30% of people over 75 years old have overactive bladder [OAB]). Previous studies showed that older women with oAB with or without urinary incontinence (UI) are prone to have gait disorders (decrease of gait speed and step width and increase of number of step). Besides UI, it is more likely the strong desire to void (SDV) that seems to impact gait and balance control. In older women with UI, balance on stabilometric parameters has been affected with an increase of the center of pression (COP) sway range, COP area and rambling trajectory. SDV seems to act like an additional cognitive task.

A similar and increased reaction time has been observed in comparing with a distracting task in healthy volunteers. In older people who are susceptible to distracting task, SDV may alters balance and gait.

The primary objective of this prospective study is to assess the impact of SDV on stabilometric parameters (center of foot pressure (COP) area, the distance travelled made by COP, the mean X-axis displacement and the mean Y-axis displacement) compared to the "empty bladder" condition.

The secondary objectives are assessing the impact of a cognitive task (verbal fluency) on stabilometric parameters in comparison with the "no cognitive task condition" and the "SDV condition"; and assessing the impact of "SDV condition" on balance and gait clinical evaluation (Timed up and go test, unipedal stance test, Berg scale, 10m walking speed, 5 chair stand) This prospective study will take place in a rehabilitation department during a 2hours-consultation. The eligible criteria are: women over 65 years old, with OAB with or without UI, able to walk without mobility equipment without neurologic pathology or spine surgery, without severe cognitive impairment (MMSE > 24) or legal protection, and who agree to be involved in the study. OAB was defined by urinary urgency, usually with urinary frequency and nocturia, with or without urgency urinary incontinence.

The included women will first have a standard urinary consultation in which comorbidities, treatments and urinary symptoms will be recorded. Participants will also have questionnaires on urinary symptoms (Urinary Symptom Profile and Incontinence Consultation Incontinence Questionnaires) and the Mini Mental Status Examination (assessing cognitive functions).

Then, participants will be evaluated on balance and gait clinical and instrumental parameters under "SDV" and "empty bladder" conditions. The order of these evaluations (SDV/empty bladder) is randomized by computer. The clinical evaluations are the Timed up and go test, the unipedal stance test, the Berg scale, the 10m walking speed test and the 5-chair-stand test. The stabilometry evaluation (recording the center of foot pressure (COP) area, the distance travelled made by COP, the mean X-axis displacement and the mean Y-axis displacement) will be on a force platform under 4 conditions: SDV with and without verbal fluency and empty bladder with and without verbal fluency.

The stabilographic parameters will be analyzed using a two-way repeated measures ANOVAs. The repeated factors are the SDV and empty bladder condition and with or without verbal fluency. Four testing combinations of these factors will be used: SDV/with verbal fluency, SDV/without verbal fluency, empty bladder/with verbal fluency and empty bladder/without verbal fluency. The ANOVA results will be used to calculate the F statistics for each main effect and interaction. The post-hoc comparisons will be performed using the Bonferroni test. The level of statistical significance was set in all tests at P≤0.05.

Thus, if we show that SDV may impact balance in geriatric population it will lead to the importance to identify and treat LUTS as potential fall risk factor in order to decrease falls incidence in this population.