Changes inherent to the aging process may be related to the increased prevalence of voiding dysfunction in older women, including overactive bladder (OAB) (1). Parasacral transcutaneous electrical stimulation (PTES) is used as a minimally invasive intervention alternative for the treatment of OAB, and its results are evidenced by the improvement of the clinical picture and urodynamic variables in children, and by the ability to produce effects similar to tibial nerve electrostimulation when quality of life and voiding habits in elderly women were studied (2). It is believed that the mechanism of action of PTES is based on the activation of large-caliber afferent fibers, which suppress information from Aδ and C fibers (physiologically involved in the bladder sensory mechanism), resulting in the non-activation of the micturition reflex. In addition, stimulation of sacral fibers produces increased muscle tone in the pelvic floor and activation of the sympathetic efferent fibers, resulting in the activation of the inhibitory reflexes involved in the bladder filling phase (3). The study aims to evaluate the effects of PTES on voiding habits and quality of life in older women with OAB.

Using a randomized clinical trial study design with blinded evaluators, women were recruited into two groups, control (G1) and intervention (G2). The eligibility criteria were women over 60 years old and diagnosed with OAB, identified by a score greater than or equal to 8 through the Overactive Bladder questionnaire - version 8 (OAB-V8). Women with lower urinary tract infection, history of drug or physiotherapy treatment for OAB in the last six months, underlying neurological diseases, history of genital-urinary neoplasia, previous pelvic irradiation, severe genital prolapse assessed on the Baden & Walker Scale, or presence of a cardiac pacemaker were excluded. The instruments for evaluating voiding habits and quality of life were a voiding diary of 3 days, ICIQ-OAB (International Consultation on Incontinence Questionnaire Overactive Bladder), and ICIQ-SF (International Consultation on Incontinence Questionnaire-Short Form). The G1 participants received behavioral therapy as an intervention through an educational lecture on voiding habits held in two meetings, once a week, lasting approximately 15 minutes each. At the first meeting, an educational booklet was also given to each participant. The guidelines included: a) positioning in the toilet; b) programmed urination; c) programmed water intake; and d) control of irritating foods. The G2 received behavioral therapy associated with PTES, which was carried out in 8 meetings, twice a week, lasting 30 minutes each and with an interval of 24 hours between sessions. The equipment used for electrostimulation was DUALPEX 961, Quark®. A pair of superficial silicone electrodes, measuring 5 cm by 7 cm, was used, with its surface covered by gel and positioned on the postero-superior iliac spines, in the transverse position. Adhesive tape was used to fix the electrodes. The parameters used for stimulation were: 10 Hz frequency, 700 µs pulse width, and maximum tolerated intensity. The final evaluation was carried out by the same evaluating physiotherapist, 5 weeks after the beginning of the treatment. The sample size calculation was performed based on a pilot study with 16 voluntary participants, with 8 participants in each group. The G*Power 3.1.9.4 program was used to generate the sample with a significance level of 5% and 20% error. Considering the number of emergency episodes, a sample of 74 participants was required. Statistical analysis was performed using the R version 3.6 program. The normality was verified by the Kolmogorov-Smirnov test. A non-parametric test was used thus, results are shown as median and mean±SD. Categorical data analysis was performed using the Chi-square test. Pre- and post-intervention in each group and between groups were performed using the paired Mann-Whitney test. All randomized participants had their data analyzed considering the group average for the missing data. The significance level was set as α = 0.05.

A sample of 75 participants who met the eligibility criteria were selected for convenience, however, 37 were excluded because they had a history of drug or physical therapy treatment for OAB in the last six months (n=14), underlying neurological diseases (n=12), urinary tract infection (n=1), previous pelvic irradiation (n=1), advanced genital prolapse assessed by the Baden & Walker Scale (n=6) and who used a cardiac pacemaker (n=1). Two participants were excluded because they refused to undergo a physical examination. In total, 38 participants were randomized, n=19 in G1 and n=19 in G2.

Both groups were homogeneous in terms of sociodemographic characteristics, clinical history and the scores of the assessment instruments (Table 1). There was clinical improvement in both groups in the quality of life measured by the ICIQ-OAB and ICIQ-SF scores; however, there was a reduction in the degree of discomfort in the symptoms of OAB only in G2. Regarding urination habits, clinical improvement was observed only for nocturia in G2. There was no significant difference between groups for any of the variables (Table 2).

Parasacral electrical stimulation associated or not to behavioral therapy improved voiding habits and quality of life. The association between these two treatments in the sample studied showed a clinical improvement superior only to the degree of discomfort of the symptoms (frequency, urge incontinence, and urgency). However, in the intergroup comparison, there was no significant difference for any of the variables studied.

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